diff --git a/configuration/configuration.py b/configuration/configuration.py
index 1db605111..78954f935 100644
--- a/configuration/configuration.py
+++ b/configuration/configuration.py
@@ -120,6 +120,11 @@ def _read_secret(secret_name, default = None):
 CORS_ORIGIN_WHITELIST = list(filter(None, environ.get('CORS_ORIGIN_WHITELIST', 'https://localhost').split(' ')))
 CORS_ORIGIN_REGEX_WHITELIST = [re.compile(r) for r in list(filter(None, environ.get('CORS_ORIGIN_REGEX_WHITELIST', '').split(' ')))]
 
+# Cross-Site-Request-Forgery-Attack settings. If Netbox is sitting behind a reverse proxy, you might need to set the CSRF_TRUSTED_ORIGINS flag.
+# Django 4.0 requires to specify the URL Scheme in this setting. An example environment variable could be specified like:
+# CSRF_TRUSTED_ORIGINS=https://demo.netbox.dev http://demo.netbox.dev
+CSRF_TRUSTED_ORIGINS = list(filter(None, environ.get('CSRF_TRUSTED_ORIGINS', '').split(' ')))
+
 # Set to True to enable server debugging. WARNING: Debugging introduces a substantial performance penalty and may reveal
 # sensitive information about your installation. Only enable debugging while performing testing. Never enable debugging
 # on a production system.
diff --git a/initializers/dcim_interfaces.yml b/initializers/dcim_interfaces.yml
index 40305306b..4db416f27 100644
--- a/initializers/dcim_interfaces.yml
+++ b/initializers/dcim_interfaces.yml
@@ -8,6 +8,15 @@
 ##
 ## Examples:
 
+# - device: server01
+#   name: ath0
+#   type: 1000base-t
+#   lag: ae0
+#   bridge: br0
+# - device: server01
+#   name: ath1
+#   type: 1000base-t
+#   parent: ath0
 # - device: server01
 #   enabled: true
 #   type: virtual
diff --git a/initializers/device_types.yml b/initializers/device_types.yml
index 88798b5b2..ffb45fe03 100644
--- a/initializers/device_types.yml
+++ b/initializers/device_types.yml
@@ -21,3 +21,36 @@
 #   slug: other
 #   custom_field_data:
 #     text_field: Description
+#   interfaces:
+#     - name: eth0
+#       type: 1000base-t
+#       mgmt_only: True
+#     - name: eth1
+#       type: 1000base-t
+#   console_server_ports:
+#     - name_template: ttyS[1-48]
+#       type: rj-45
+#   power_ports:
+#     - name: psu0  # both non-template and template field specified; non-template field takes precedence
+#       name_template: psu[0,1]
+#       type: iec-60320-c14
+#       maximum_draw: 35
+#       allocated_draw: 35
+#   front_ports:
+#     - name_template: front[1,2]
+#       type: 8p8c
+#       rear_port_template: rear[0,1]
+#       rear_port_position_template: "[1,2]"
+#   rear_ports:
+#     - name_template: rear[0,1]
+#       type: 8p8c
+#       positions_template: "[3,2]"
+#   device_bays:
+#     - name_template: bay[0-9]
+#       label_template: test[0-5,9,6-8]
+#       description: Test description
+#   power_outlets:
+#     - name_template: outlet[0,1]
+#       type: iec-60320-c5
+#       power_port: psu0
+#       feed_leg: B
diff --git a/initializers/users.yml b/initializers/users.yml
index c163d5043..d6484c209 100644
--- a/initializers/users.yml
+++ b/initializers/users.yml
@@ -4,6 +4,7 @@
 #   password: reader
 # writer:
 #   password: writer
+#   api_token: "" # a token is generated automatically unless the value is explicity set to empty
 # jdoe:
 #   first_name: John
 #   last_name: Doe
diff --git a/startup_scripts/000_users.py b/startup_scripts/000_users.py
index 1435d8128..7ca63052f 100644
--- a/startup_scripts/000_users.py
+++ b/startup_scripts/000_users.py
@@ -9,13 +9,17 @@
     sys.exit()
 
 for username, user_details in users.items():
-    if not User.objects.filter(username=username):
-        user = User.objects.create_user(
-            username=username,
-            password=user_details.get("password", 0) or User.objects.make_random_password(),
-        )
 
-        print("👤 Created user", username)
+    api_token = user_details.pop("api_token", Token.generate_key())
+    password = user_details.pop("password", User.objects.make_random_password())
+
+    user, created = User.objects.get_or_create(username=username, defaults=user_details)
+
+    if created:
+        user.set_password(password)
+        user.save()
 
-        if user_details.get("api_token", 0):
-            Token.objects.create(user=user, key=user_details["api_token"])
+        if api_token:
+            Token.objects.get_or_create(user=user, key=api_token)
+
+        print("👤 Created user", username)
diff --git a/startup_scripts/020_object_permissions.py b/startup_scripts/020_object_permissions.py
index 8a5ecd40b..562a09c26 100644
--- a/startup_scripts/020_object_permissions.py
+++ b/startup_scripts/020_object_permissions.py
@@ -14,9 +14,11 @@
 
     object_permission, created = ObjectPermission.objects.get_or_create(
         name=permission_name,
-        description=permission_details["description"],
-        enabled=permission_details["enabled"],
-        actions=permission_details["actions"],
+        defaults={
+            "description": permission_details["description"],
+            "enabled": permission_details["enabled"],
+            "actions": permission_details["actions"],
+        },
     )
 
     if permission_details.get("object_types", 0):
diff --git a/startup_scripts/040_custom_links.py b/startup_scripts/040_custom_links.py
index 40144bd13..d8c0bba32 100644
--- a/startup_scripts/040_custom_links.py
+++ b/startup_scripts/040_custom_links.py
@@ -2,7 +2,7 @@
 
 from django.contrib.contenttypes.models import ContentType
 from extras.models import CustomLink
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 custom_links = load_yaml("/opt/netbox/initializers/custom_links.yml")
 
@@ -28,6 +28,8 @@ def get_content_type_id(content_type):
         )
         continue
 
-    custom_link, created = CustomLink.objects.get_or_create(**link)
+    matching_params, defaults = split_params(link)
+    custom_link, created = CustomLink.objects.get_or_create(**matching_params, defaults=defaults)
+
     if created:
         print("🔗 Created Custom Link '{0}'".format(custom_link.name))
diff --git a/startup_scripts/050_tags.py b/startup_scripts/050_tags.py
index e50a000cc..06a18cb9f 100644
--- a/startup_scripts/050_tags.py
+++ b/startup_scripts/050_tags.py
@@ -1,7 +1,7 @@
 import sys
 
 from extras.models import Tag
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from utilities.choices import ColorChoices
 
 tags = load_yaml("/opt/netbox/initializers/tags.yml")
@@ -17,7 +17,8 @@
             if color in color_tpl:
                 params["color"] = color_tpl[0]
 
-    tag, created = Tag.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    tag, created = Tag.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🎨 Created Tag", tag.name)
diff --git a/startup_scripts/060_webhooks.py b/startup_scripts/060_webhooks.py
index 8787f5f40..9de6e7e31 100644
--- a/startup_scripts/060_webhooks.py
+++ b/startup_scripts/060_webhooks.py
@@ -2,7 +2,7 @@
 
 from django.contrib.contenttypes.models import ContentType
 from extras.models import Webhook
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 webhooks = load_yaml("/opt/netbox/initializers/webhooks.yml")
 
@@ -26,7 +26,9 @@ def get_content_type_id(hook_name, content_type):
     except ContentType.DoesNotExist:
         continue
 
-    webhook, created = Webhook.objects.get_or_create(**hook)
+    matching_params, defaults = split_params(hook)
+    webhook, created = Webhook.objects.get_or_create(**matching_params, defaults=defaults)
+
     if created:
         webhook.content_types.set(obj_type_ids)
         webhook.save()
diff --git a/startup_scripts/070_tenant_groups.py b/startup_scripts/070_tenant_groups.py
index 65cf15541..0bfebadbe 100644
--- a/startup_scripts/070_tenant_groups.py
+++ b/startup_scripts/070_tenant_groups.py
@@ -1,6 +1,6 @@
 import sys
 
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from tenancy.models import TenantGroup
 
 tenant_groups = load_yaml("/opt/netbox/initializers/tenant_groups.yml")
@@ -9,7 +9,8 @@
     sys.exit()
 
 for params in tenant_groups:
-    tenant_group, created = TenantGroup.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    tenant_group, created = TenantGroup.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🔳 Created Tenant Group", tenant_group.name)
diff --git a/startup_scripts/080_tenants.py b/startup_scripts/080_tenants.py
index 7b1a629f0..88d68b7b7 100644
--- a/startup_scripts/080_tenants.py
+++ b/startup_scripts/080_tenants.py
@@ -1,6 +1,11 @@
 import sys
 
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant, TenantGroup
 
 tenants = load_yaml("/opt/netbox/initializers/tenants.yml")
@@ -20,9 +25,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    tenant, created = Tenant.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    tenant, created = Tenant.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(tenant, custom_field_data)
-
         print("👩‍💻 Created Tenant", tenant.name)
+
+    set_custom_fields_values(tenant, custom_field_data)
diff --git a/startup_scripts/090_regions.py b/startup_scripts/090_regions.py
index 9d5c91f92..592c4c5ac 100644
--- a/startup_scripts/090_regions.py
+++ b/startup_scripts/090_regions.py
@@ -1,7 +1,7 @@
 import sys
 
 from dcim.models import Region
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 regions = load_yaml("/opt/netbox/initializers/regions.yml")
 
@@ -19,7 +19,8 @@
 
             params[assoc] = model.objects.get(**query)
 
-    region, created = Region.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    region, created = Region.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🌐 Created region", region.name)
diff --git a/startup_scripts/110_sites.py b/startup_scripts/110_sites.py
index f7851391a..c310e1423 100644
--- a/startup_scripts/110_sites.py
+++ b/startup_scripts/110_sites.py
@@ -1,7 +1,12 @@
 import sys
 
 from dcim.models import Region, Site
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 
 sites = load_yaml("/opt/netbox/initializers/sites.yml")
@@ -21,9 +26,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    site, created = Site.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    site, created = Site.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(site, custom_field_data)
-
         print("📍 Created site", site.name)
+
+    set_custom_fields_values(site, custom_field_data)
diff --git a/startup_scripts/120_locations.py b/startup_scripts/120_locations.py
index d8a2c5a11..6a269b24e 100644
--- a/startup_scripts/120_locations.py
+++ b/startup_scripts/120_locations.py
@@ -1,13 +1,14 @@
 import sys
 
 from dcim.models import Location, Site
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 rack_groups = load_yaml("/opt/netbox/initializers/locations.yml")
 
 if rack_groups is None:
     sys.exit()
 
+match_params = ["name", "slug", "site"]
 required_assocs = {"site": (Site, "name")}
 
 for params in rack_groups:
@@ -17,7 +18,8 @@
         query = {field: params.pop(assoc)}
         params[assoc] = model.objects.get(**query)
 
-    location, created = Location.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    location, created = Location.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🎨 Created location", location.name)
diff --git a/startup_scripts/130_rack_roles.py b/startup_scripts/130_rack_roles.py
index 585040558..8d43237be 100644
--- a/startup_scripts/130_rack_roles.py
+++ b/startup_scripts/130_rack_roles.py
@@ -1,7 +1,7 @@
 import sys
 
 from dcim.models import RackRole
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from utilities.choices import ColorChoices
 
 rack_roles = load_yaml("/opt/netbox/initializers/rack_roles.yml")
@@ -17,7 +17,8 @@
             if color in color_tpl:
                 params["color"] = color_tpl[0]
 
-    rack_role, created = RackRole.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    rack_role, created = RackRole.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🎨 Created rack role", rack_role.name)
diff --git a/startup_scripts/140_racks.py b/startup_scripts/140_racks.py
index b2cfc801c..f3dc1452b 100644
--- a/startup_scripts/140_racks.py
+++ b/startup_scripts/140_racks.py
@@ -1,7 +1,12 @@
 import sys
 
 from dcim.models import Location, Rack, RackRole, Site
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 
 racks = load_yaml("/opt/netbox/initializers/racks.yml")
@@ -9,8 +14,8 @@
 if racks is None:
     sys.exit()
 
+match_params = ["name", "site"]
 required_assocs = {"site": (Site, "name")}
-
 optional_assocs = {
     "role": (RackRole, "name"),
     "tenant": (Tenant, "name"),
@@ -33,9 +38,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    rack, created = Rack.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    rack, created = Rack.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(rack, custom_field_data)
-
         print("🔳 Created rack", rack.site, rack.name)
+
+    set_custom_fields_values(rack, custom_field_data)
diff --git a/startup_scripts/150_power_panels.py b/startup_scripts/150_power_panels.py
index 8542435bc..1397a9392 100644
--- a/startup_scripts/150_power_panels.py
+++ b/startup_scripts/150_power_panels.py
@@ -1,15 +1,20 @@
 import sys
 
 from dcim.models import Location, PowerPanel, Site
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 
 power_panels = load_yaml("/opt/netbox/initializers/power_panels.yml")
 
 if power_panels is None:
     sys.exit()
 
+match_params = ["name", "site"]
 required_assocs = {"site": (Site, "name")}
-
 optional_assocs = {"location": (Location, "name")}
 
 for params in power_panels:
@@ -28,9 +33,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    power_panel, created = PowerPanel.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    power_panel, created = PowerPanel.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(power_panel, custom_field_data)
-
         print("⚡ Created Power Panel", power_panel.site, power_panel.name)
+
+    set_custom_fields_values(power_panel, custom_field_data)
diff --git a/startup_scripts/160_power_feeds.py b/startup_scripts/160_power_feeds.py
index f5aa5b570..7b3e6acef 100644
--- a/startup_scripts/160_power_feeds.py
+++ b/startup_scripts/160_power_feeds.py
@@ -1,15 +1,20 @@
 import sys
 
 from dcim.models import PowerFeed, PowerPanel, Rack
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 
 power_feeds = load_yaml("/opt/netbox/initializers/power_feeds.yml")
 
 if power_feeds is None:
     sys.exit()
 
+match_params = ["name", "power_panel"]
 required_assocs = {"power_panel": (PowerPanel, "name")}
-
 optional_assocs = {"rack": (Rack, "name")}
 
 for params in power_feeds:
@@ -28,9 +33,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    power_feed, created = PowerFeed.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    power_feed, created = PowerFeed.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(power_feed, custom_field_data)
-
         print("⚡ Created Power Feed", power_feed.name)
+
+    set_custom_fields_values(power_feed, custom_field_data)
diff --git a/startup_scripts/170_manufacturers.py b/startup_scripts/170_manufacturers.py
index d11b44092..c105a4651 100644
--- a/startup_scripts/170_manufacturers.py
+++ b/startup_scripts/170_manufacturers.py
@@ -1,7 +1,7 @@
 import sys
 
 from dcim.models import Manufacturer
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 manufacturers = load_yaml("/opt/netbox/initializers/manufacturers.yml")
 
@@ -9,7 +9,8 @@
     sys.exit()
 
 for params in manufacturers:
-    manufacturer, created = Manufacturer.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    manufacturer, created = Manufacturer.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🏭 Created Manufacturer", manufacturer.name)
diff --git a/startup_scripts/180_device_roles.py b/startup_scripts/180_device_roles.py
index 635acff54..3cea0f10d 100644
--- a/startup_scripts/180_device_roles.py
+++ b/startup_scripts/180_device_roles.py
@@ -1,7 +1,7 @@
 import sys
 
 from dcim.models import DeviceRole
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from utilities.choices import ColorChoices
 
 device_roles = load_yaml("/opt/netbox/initializers/device_roles.yml")
@@ -18,7 +18,8 @@
             if color in color_tpl:
                 params["color"] = color_tpl[0]
 
-    device_role, created = DeviceRole.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    device_role, created = DeviceRole.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🎨 Created device role", device_role.name)
diff --git a/startup_scripts/190_device_types.py b/startup_scripts/190_device_types.py
index 0d3050b45..d1548058c 100644
--- a/startup_scripts/190_device_types.py
+++ b/startup_scripts/190_device_types.py
@@ -1,20 +1,96 @@
 import sys
+from typing import List
 
 from dcim.models import DeviceType, Manufacturer, Region
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from dcim.models.device_component_templates import (
+    ConsolePortTemplate,
+    ConsoleServerPortTemplate,
+    DeviceBayTemplate,
+    FrontPortTemplate,
+    InterfaceTemplate,
+    PowerOutletTemplate,
+    PowerPortTemplate,
+    RearPortTemplate,
+)
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
+from utilities.forms.utils import expand_alphanumeric_pattern
+
+
+def expand_templates(params: List[dict], device_type: DeviceType) -> List[dict]:
+    templateable_fields = ["name", "label", "positions", "rear_port", "rear_port_position"]
+
+    expanded = []
+    for param in params:
+        param["device_type"] = device_type
+        expanded_fields = {}
+        has_plain_fields = False
+
+        for field in templateable_fields:
+            template_value = param.pop(f"{field}_template", None)
+
+            if field in param:
+                has_plain_fields = True
+                expanded.append(param)
+            elif template_value:
+                expanded_fields[field] = list(expand_alphanumeric_pattern(template_value))
+
+        if expanded_fields and has_plain_fields:
+            raise ValueError(f"Mix of plain and template keys provided for {templateable_fields}")
+
+        if not expanded_fields:
+            continue
+
+        elements = list(expanded_fields.values())
+        master_len = len(elements[0])
+        if not all([len(elem) == master_len for elem in elements]):
+            raise ValueError(
+                f"Number of elements in template fields "
+                f"{list(expanded_fields.keys())} must be equal"
+            )
+
+        for idx in range(master_len):
+            tmp = param.copy()
+            for field, value in expanded_fields.items():
+                if field in nested_assocs:
+                    model, match_key = nested_assocs[field]
+                    query = {match_key: value[idx], "device_type": device_type}
+                    tmp[field] = model.objects.get(**query)
+                else:
+                    tmp[field] = value[idx]
+            expanded.append(tmp)
+    return expanded
+
 
 device_types = load_yaml("/opt/netbox/initializers/device_types.yml")
 
 if device_types is None:
     sys.exit()
 
+match_params = ["manufacturer", "model", "slug"]
 required_assocs = {"manufacturer": (Manufacturer, "name")}
-
 optional_assocs = {"region": (Region, "name"), "tenant": (Tenant, "name")}
+nested_assocs = {"rear_port": (RearPortTemplate, "name"), "power_port": (PowerPortTemplate, "name")}
+
+supported_components = {
+    "interfaces": (InterfaceTemplate, ["name"]),
+    "console_ports": (ConsolePortTemplate, ["name"]),
+    "console_server_ports": (ConsoleServerPortTemplate, ["name"]),
+    "power_ports": (PowerPortTemplate, ["name"]),
+    "power_outlets": (PowerOutletTemplate, ["name"]),
+    "rear_ports": (RearPortTemplate, ["name"]),
+    "front_ports": (FrontPortTemplate, ["name"]),
+    "device_bays": (DeviceBayTemplate, ["name"]),
+}
 
 for params in device_types:
     custom_field_data = pop_custom_fields(params)
+    components = [(v[0], v[1], params.pop(k, [])) for k, v in supported_components.items()]
 
     for assoc, details in required_assocs.items():
         model, field = details
@@ -29,9 +105,36 @@
 
             params[assoc] = model.objects.get(**query)
 
-    device_type, created = DeviceType.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    device_type, created = DeviceType.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(device_type, custom_field_data)
-
         print("🔡 Created device type", device_type.manufacturer, device_type.model)
+
+    set_custom_fields_values(device_type, custom_field_data)
+
+    for component in components:
+        c_model, c_match_params, c_params = component
+        c_match_params.append("device_type")
+
+        if not c_params:
+            continue
+
+        expanded_c_params = expand_templates(c_params, device_type)
+
+        for n_assoc, n_details in nested_assocs.items():
+            n_model, n_field = n_details
+            for c_param in expanded_c_params:
+                if n_assoc in c_param:
+                    n_query = {n_field: c_param[n_assoc], "device_type": device_type}
+                    c_param[n_assoc] = n_model.objects.get(**n_query)
+
+        for new_param in expanded_c_params:
+            new_matching_params, new_defaults = split_params(new_param, c_match_params)
+            new_obj, new_obj_created = c_model.objects.get_or_create(
+                **new_matching_params, defaults=new_defaults
+            )
+            if new_obj_created:
+                print(
+                    f"🧷  Created {c_model._meta} {new_obj} component for device type {device_type}"
+                )
diff --git a/startup_scripts/200_devices.py b/startup_scripts/200_devices.py
index 423b7c9de..189471ca8 100644
--- a/startup_scripts/200_devices.py
+++ b/startup_scripts/200_devices.py
@@ -1,7 +1,12 @@
 import sys
 
 from dcim.models import Device, DeviceRole, DeviceType, Location, Platform, Rack, Site
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 from virtualization.models import Cluster
 
@@ -10,12 +15,12 @@
 if devices is None:
     sys.exit()
 
+match_params = ["device_type", "name", "site"]
 required_assocs = {
     "device_role": (DeviceRole, "name"),
     "device_type": (DeviceType, "model"),
     "site": (Site, "name"),
 }
-
 optional_assocs = {
     "tenant": (Tenant, "name"),
     "platform": (Platform, "name"),
@@ -27,7 +32,7 @@
 for params in devices:
     custom_field_data = pop_custom_fields(params)
 
-    # primary ips are handled later in `270_primary_ips.py`
+    # primary ips are handled later in `380_primary_ips.py`
     params.pop("primary_ip4", None)
     params.pop("primary_ip6", None)
 
@@ -44,9 +49,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    device, created = Device.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    device, created = Device.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(device, custom_field_data)
-
         print("🖥️  Created device", device.name)
+
+    set_custom_fields_values(device, custom_field_data)
diff --git a/startup_scripts/210_dcim_interfaces.py b/startup_scripts/210_dcim_interfaces.py
index a8026282f..6e57e73ce 100644
--- a/startup_scripts/210_dcim_interfaces.py
+++ b/startup_scripts/210_dcim_interfaces.py
@@ -1,27 +1,70 @@
 import sys
 
 from dcim.models import Device, Interface
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 
 interfaces = load_yaml("/opt/netbox/initializers/dcim_interfaces.yml")
 
 if interfaces is None:
     sys.exit()
 
+match_params = ["device", "name"]
 required_assocs = {"device": (Device, "name")}
+related_assocs = {
+    "bridge": (Interface, "name"),
+    "lag": (Interface, "name"),
+    "parent": (Interface, "name"),
+}
 
 for params in interfaces:
     custom_field_data = pop_custom_fields(params)
 
+    related_interfaces = {k: params.pop(k, None) for k in related_assocs}
+
     for assoc, details in required_assocs.items():
         model, field = details
         query = {field: params.pop(assoc)}
 
         params[assoc] = model.objects.get(**query)
 
-    interface, created = Interface.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    interface, created = Interface.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(interface, custom_field_data)
+        print(f"🧷 Created interface {interface} on {interface.device}")
+
+    set_custom_fields_values(interface, custom_field_data)
+
+    for related_field, related_value in related_interfaces.items():
+        if not related_value:
+            continue
+
+        r_model, r_field = related_assocs[related_field]
+
+        if related_field == "parent" and not interface.parent_id:
+            query = {r_field: related_value, "device": interface.device}
+            try:
+                related_obj = r_model.objects.get(**query)
+            except Interface.DoesNotExist:
+                print(f"⚠️ Could not find parent interface with: {query} for interface {interface}")
+                raise
+
+            interface.parent_id = related_obj.id
+            interface.save()
+            print(
+                f"🧷 Attached interface {interface} on {interface.device} "
+                f"to parent {related_obj}"
+            )
+        else:
+            query = {r_field: related_value, "device": interface.device, "type": related_field}
+            related_obj, rel_obj_created = r_model.objects.get_or_create(**query)
 
-        print("🧷 Created interface", interface.name, interface.device.name)
+            if rel_obj_created:
+                setattr(interface, f"{related_field}_id", related_obj.id)
+                interface.save()
+                print(f"🧷 Created {related_field} interface {interface} on {interface.device}")
diff --git a/startup_scripts/220_platforms.py b/startup_scripts/220_platforms.py
index 633b89ffc..73905d4e1 100644
--- a/startup_scripts/220_platforms.py
+++ b/startup_scripts/220_platforms.py
@@ -1,7 +1,7 @@
 import sys
 
 from dcim.models import Manufacturer, Platform
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 platforms = load_yaml("/opt/netbox/initializers/platforms.yml")
 
@@ -21,7 +21,8 @@
 
             params[assoc] = model.objects.get(**query)
 
-    platform, created = Platform.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    platform, created = Platform.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("💾 Created platform", platform.name)
diff --git a/startup_scripts/230_route_targets.py b/startup_scripts/230_route_targets.py
index e1c82217e..12ca9a591 100644
--- a/startup_scripts/230_route_targets.py
+++ b/startup_scripts/230_route_targets.py
@@ -1,7 +1,12 @@
 import sys
 
 from ipam.models import RouteTarget
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 
 route_targets = load_yaml("/opt/netbox/initializers/route_targets.yml")
@@ -21,9 +26,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    route_target, created = RouteTarget.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    route_target, created = RouteTarget.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(route_target, custom_field_data)
-
         print("🎯 Created Route Target", route_target.name)
+
+    set_custom_fields_values(route_target, custom_field_data)
diff --git a/startup_scripts/240_vrfs.py b/startup_scripts/240_vrfs.py
index a67c8c8cb..1b4cd1a97 100644
--- a/startup_scripts/240_vrfs.py
+++ b/startup_scripts/240_vrfs.py
@@ -1,7 +1,12 @@
 import sys
 
 from ipam.models import VRF
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 
 vrfs = load_yaml("/opt/netbox/initializers/vrfs.yml")
@@ -9,6 +14,7 @@
 if vrfs is None:
     sys.exit()
 
+match_params = ["name", "rd"]
 optional_assocs = {"tenant": (Tenant, "name")}
 
 for params in vrfs:
@@ -21,9 +27,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    vrf, created = VRF.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    vrf, created = VRF.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(vrf, custom_field_data)
-
         print("📦 Created VRF", vrf.name)
+
+    set_custom_fields_values(vrf, custom_field_data)
diff --git a/startup_scripts/250_rirs.py b/startup_scripts/250_rirs.py
index 0e0df2008..08d1703af 100644
--- a/startup_scripts/250_rirs.py
+++ b/startup_scripts/250_rirs.py
@@ -1,7 +1,7 @@
 import sys
 
 from ipam.models import RIR
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 rirs = load_yaml("/opt/netbox/initializers/rirs.yml")
 
@@ -9,7 +9,8 @@
     sys.exit()
 
 for params in rirs:
-    rir, created = RIR.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    rir, created = RIR.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🗺️ Created RIR", rir.name)
diff --git a/startup_scripts/260_asns.py b/startup_scripts/260_asns.py
index 893f3ba91..93776d247 100644
--- a/startup_scripts/260_asns.py
+++ b/startup_scripts/260_asns.py
@@ -1,7 +1,7 @@
 import sys
 
 from ipam.models import ASN, RIR
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from tenancy.models import Tenant
 
 asns = load_yaml("/opt/netbox/initializers/asns.yml")
@@ -9,8 +9,8 @@
 if asns is None:
     sys.exit()
 
+match_params = ["asn", "rir"]
 required_assocs = {"rir": (RIR, "name")}
-
 optional_assocs = {"tenant": (Tenant, "name")}
 
 for params in asns:
@@ -27,7 +27,8 @@
 
             params[assoc] = model.objects.get(**query)
 
-    asn, created = ASN.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    asn, created = ASN.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print(f"🔡 Created ASN {asn.asn}")
diff --git a/startup_scripts/270_aggregates.py b/startup_scripts/270_aggregates.py
index c638e6f81..d37c4cc7d 100644
--- a/startup_scripts/270_aggregates.py
+++ b/startup_scripts/270_aggregates.py
@@ -2,7 +2,12 @@
 
 from ipam.models import RIR, Aggregate
 from netaddr import IPNetwork
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 
 aggregates = load_yaml("/opt/netbox/initializers/aggregates.yml")
@@ -10,8 +15,8 @@
 if aggregates is None:
     sys.exit()
 
+match_params = ["prefix", "rir"]
 required_assocs = {"rir": (RIR, "name")}
-
 optional_assocs = {
     "tenant": (Tenant, "name"),
 }
@@ -34,9 +39,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    aggregate, created = Aggregate.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    aggregate, created = Aggregate.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(aggregate, custom_field_data)
-
         print("🗞️ Created Aggregate", aggregate.prefix)
+
+    set_custom_fields_values(aggregate, custom_field_data)
diff --git a/startup_scripts/280_prefix_vlan_roles.py b/startup_scripts/280_prefix_vlan_roles.py
index ec359fbc0..c17feb853 100644
--- a/startup_scripts/280_prefix_vlan_roles.py
+++ b/startup_scripts/280_prefix_vlan_roles.py
@@ -1,7 +1,7 @@
 import sys
 
 from ipam.models import Role
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 
 roles = load_yaml("/opt/netbox/initializers/prefix_vlan_roles.yml")
 
@@ -9,7 +9,8 @@
     sys.exit()
 
 for params in roles:
-    role, created = Role.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    role, created = Role.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("⛹️‍ Created Prefix/VLAN Role", role.name)
diff --git a/startup_scripts/290_cluster_types.py b/startup_scripts/290_cluster_types.py
index 9f361b1cf..642bc7a5c 100644
--- a/startup_scripts/290_cluster_types.py
+++ b/startup_scripts/290_cluster_types.py
@@ -1,6 +1,6 @@
 import sys
 
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from virtualization.models import ClusterType
 
 cluster_types = load_yaml("/opt/netbox/initializers/cluster_types.yml")
@@ -9,7 +9,8 @@
     sys.exit()
 
 for params in cluster_types:
-    cluster_type, created = ClusterType.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    cluster_type, created = ClusterType.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
         print("🧰 Created Cluster Type", cluster_type.name)
diff --git a/startup_scripts/300_cluster_groups.py b/startup_scripts/300_cluster_groups.py
index fedd292ec..a8e357337 100644
--- a/startup_scripts/300_cluster_groups.py
+++ b/startup_scripts/300_cluster_groups.py
@@ -1,6 +1,6 @@
 import sys
 
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from virtualization.models import ClusterGroup
 
 cluster_groups = load_yaml("/opt/netbox/initializers/cluster_groups.yml")
@@ -9,7 +9,10 @@
     sys.exit()
 
 for params in cluster_groups:
-    cluster_group, created = ClusterGroup.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    cluster_group, created = ClusterGroup.objects.get_or_create(
+        **matching_params, defaults=defaults
+    )
 
     if created:
         print("🗄️ Created Cluster Group", cluster_group.name)
diff --git a/startup_scripts/310_clusters.py b/startup_scripts/310_clusters.py
index 2748f2038..e36a5f9e7 100644
--- a/startup_scripts/310_clusters.py
+++ b/startup_scripts/310_clusters.py
@@ -1,7 +1,12 @@
 import sys
 
 from dcim.models import Site
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 from virtualization.models import Cluster, ClusterGroup, ClusterType
 
@@ -10,8 +15,8 @@
 if clusters is None:
     sys.exit()
 
+match_params = ["name", "type"]
 required_assocs = {"type": (ClusterType, "name")}
-
 optional_assocs = {
     "site": (Site, "name"),
     "group": (ClusterGroup, "name"),
@@ -34,9 +39,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    cluster, created = Cluster.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    cluster, created = Cluster.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(cluster, custom_field_data)
-
         print("🗄️ Created cluster", cluster.name)
+
+    set_custom_fields_values(cluster, custom_field_data)
diff --git a/startup_scripts/320_vlan_groups.py b/startup_scripts/320_vlan_groups.py
index 2a4a33dec..a81e695f3 100644
--- a/startup_scripts/320_vlan_groups.py
+++ b/startup_scripts/320_vlan_groups.py
@@ -2,7 +2,12 @@
 
 from django.contrib.contenttypes.models import ContentType
 from ipam.models import VLANGroup
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 
 vlan_groups = load_yaml("/opt/netbox/initializers/vlan_groups.yml")
 
@@ -32,9 +37,11 @@
                 )
                 continue
             params["scope_id"] = ct.model_class().objects.get(**query).id
-    vlan_group, created = VLANGroup.objects.get_or_create(**params)
 
-    if created:
-        set_custom_fields_values(vlan_group, custom_field_data)
+    matching_params, defaults = split_params(params)
+    vlan_group, created = VLANGroup.objects.get_or_create(**matching_params, defaults=defaults)
 
+    if created:
         print("🏘️ Created VLAN Group", vlan_group.name)
+
+    set_custom_fields_values(vlan_group, custom_field_data)
diff --git a/startup_scripts/330_vlans.py b/startup_scripts/330_vlans.py
index e8ebb94f1..e378881bc 100644
--- a/startup_scripts/330_vlans.py
+++ b/startup_scripts/330_vlans.py
@@ -2,7 +2,12 @@
 
 from dcim.models import Site
 from ipam.models import VLAN, Role, VLANGroup
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant, TenantGroup
 
 vlans = load_yaml("/opt/netbox/initializers/vlans.yml")
@@ -10,6 +15,7 @@
 if vlans is None:
     sys.exit()
 
+match_params = ["name", "vid"]
 optional_assocs = {
     "site": (Site, "name"),
     "tenant": (Tenant, "name"),
@@ -28,9 +34,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    vlan, created = VLAN.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    vlan, created = VLAN.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(vlan, custom_field_data)
-
         print("🏠 Created VLAN", vlan.name)
+
+    set_custom_fields_values(vlan, custom_field_data)
diff --git a/startup_scripts/340_virtual_machines.py b/startup_scripts/340_virtual_machines.py
index 2e3f42885..51d3bc6fb 100644
--- a/startup_scripts/340_virtual_machines.py
+++ b/startup_scripts/340_virtual_machines.py
@@ -1,7 +1,12 @@
 import sys
 
 from dcim.models import DeviceRole, Platform
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 from virtualization.models import Cluster, VirtualMachine
 
@@ -10,8 +15,8 @@
 if virtual_machines is None:
     sys.exit()
 
+match_params = ["cluster", "name"]
 required_assocs = {"cluster": (Cluster, "name")}
-
 optional_assocs = {
     "tenant": (Tenant, "name"),
     "platform": (Platform, "name"),
@@ -38,9 +43,12 @@
 
             params[assoc] = model.objects.get(**query)
 
-    virtual_machine, created = VirtualMachine.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    virtual_machine, created = VirtualMachine.objects.get_or_create(
+        **matching_params, defaults=defaults
+    )
 
     if created:
-        set_custom_fields_values(virtual_machine, custom_field_data)
-
         print("🖥️ Created virtual machine", virtual_machine.name)
+
+    set_custom_fields_values(virtual_machine, custom_field_data)
diff --git a/startup_scripts/350_virtualization_interfaces.py b/startup_scripts/350_virtualization_interfaces.py
index 6ee63474c..c6bbfa050 100644
--- a/startup_scripts/350_virtualization_interfaces.py
+++ b/startup_scripts/350_virtualization_interfaces.py
@@ -1,6 +1,11 @@
 import sys
 
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from virtualization.models import VirtualMachine, VMInterface
 
 interfaces = load_yaml("/opt/netbox/initializers/virtualization_interfaces.yml")
@@ -8,6 +13,7 @@
 if interfaces is None:
     sys.exit()
 
+match_params = ["name", "virtual_machine"]
 required_assocs = {"virtual_machine": (VirtualMachine, "name")}
 
 for params in interfaces:
@@ -19,9 +25,10 @@
 
         params[assoc] = model.objects.get(**query)
 
-    interface, created = VMInterface.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    interface, created = VMInterface.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(interface, custom_field_data)
-
         print("🧷 Created interface", interface.name, interface.virtual_machine.name)
+
+    set_custom_fields_values(interface, custom_field_data)
diff --git a/startup_scripts/360_prefixes.py b/startup_scripts/360_prefixes.py
index 4e2b0d007..ffb774bfe 100644
--- a/startup_scripts/360_prefixes.py
+++ b/startup_scripts/360_prefixes.py
@@ -3,7 +3,12 @@
 from dcim.models import Site
 from ipam.models import VLAN, VRF, Prefix, Role
 from netaddr import IPNetwork
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant, TenantGroup
 
 prefixes = load_yaml("/opt/netbox/initializers/prefixes.yml")
@@ -11,6 +16,7 @@
 if prefixes is None:
     sys.exit()
 
+match_params = ["prefix", "site", "vrf", "vlan"]
 optional_assocs = {
     "site": (Site, "name"),
     "tenant": (Tenant, "name"),
@@ -31,9 +37,10 @@
             query = {field: params.pop(assoc)}
             params[assoc] = model.objects.get(**query)
 
-    prefix, created = Prefix.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    prefix, created = Prefix.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(prefix, custom_field_data)
-
         print("📌 Created Prefix", prefix.prefix)
+
+    set_custom_fields_values(prefix, custom_field_data)
diff --git a/startup_scripts/370_ip_addresses.py b/startup_scripts/370_ip_addresses.py
index 7f166f0bb..b35cb49e2 100644
--- a/startup_scripts/370_ip_addresses.py
+++ b/startup_scripts/370_ip_addresses.py
@@ -5,7 +5,12 @@
 from django.db.models import Q
 from ipam.models import VRF, IPAddress
 from netaddr import IPNetwork
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 from virtualization.models import VirtualMachine, VMInterface
 
@@ -14,10 +19,11 @@
 if ip_addresses is None:
     sys.exit()
 
+match_params = ["address", "vrf"]
 optional_assocs = {
     "tenant": (Tenant, "name"),
     "vrf": (VRF, "name"),
-    "interface": (None, None),
+    "interface": (Interface, "name"),
 }
 
 vm_interface_ct = ContentType.objects.filter(
@@ -55,9 +61,10 @@
 
                 params[assoc] = model.objects.get(**query)
 
-    ip_address, created = IPAddress.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    ip_address, created = IPAddress.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(ip_address, custom_field_data)
-
         print("🧬 Created IP Address", ip_address.address)
+
+    set_custom_fields_values(ip_address, custom_field_data)
diff --git a/startup_scripts/400_services.py b/startup_scripts/400_services.py
index a28eb09f7..a92d82b1d 100644
--- a/startup_scripts/400_services.py
+++ b/startup_scripts/400_services.py
@@ -2,7 +2,7 @@
 
 from dcim.models import Device
 from ipam.models import Service
-from startup_script_utils import load_yaml
+from startup_script_utils import load_yaml, split_params
 from virtualization.models import VirtualMachine
 
 services = load_yaml("/opt/netbox/initializers/services.yml")
@@ -10,6 +10,7 @@
 if services is None:
     sys.exit()
 
+match_params = ["name", "device", "virtual_machine"]
 optional_assocs = {
     "device": (Device, "name"),
     "virtual_machine": (VirtualMachine, "name"),
@@ -24,6 +25,7 @@
 
             params[assoc] = model.objects.get(**query)
 
+    matching_params, defaults = split_params(params, match_params)
     service, created = Service.objects.get_or_create(**params)
 
     if created:
diff --git a/startup_scripts/420_providers.py b/startup_scripts/420_providers.py
index 5c4330ad3..e68e1f369 100644
--- a/startup_scripts/420_providers.py
+++ b/startup_scripts/420_providers.py
@@ -1,7 +1,12 @@
 import sys
 
 from circuits.models import Provider
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 
 providers = load_yaml("/opt/netbox/initializers/providers.yml")
 
@@ -11,9 +16,10 @@
 for params in providers:
     custom_field_data = pop_custom_fields(params)
 
-    provider, created = Provider.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    provider, created = Provider.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(provider, custom_field_data)
-
         print("📡 Created provider", provider.name)
+
+    set_custom_fields_values(provider, custom_field_data)
diff --git a/startup_scripts/440_circuit_types.py b/startup_scripts/440_circuit_types.py
index 071793c6f..6d3f7fa3e 100644
--- a/startup_scripts/440_circuit_types.py
+++ b/startup_scripts/440_circuit_types.py
@@ -1,7 +1,12 @@
 import sys
 
 from circuits.models import CircuitType
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 
 circuit_types = load_yaml("/opt/netbox/initializers/circuit_types.yml")
 
@@ -11,9 +16,10 @@
 for params in circuit_types:
     custom_field_data = pop_custom_fields(params)
 
-    circuit_type, created = CircuitType.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params)
+    circuit_type, created = CircuitType.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(circuit_type, custom_field_data)
-
         print("⚡ Created Circuit Type", circuit_type.name)
+
+    set_custom_fields_values(circuit_type, custom_field_data)
diff --git a/startup_scripts/450_circuits.py b/startup_scripts/450_circuits.py
index f82d3b71d..68f159b5b 100644
--- a/startup_scripts/450_circuits.py
+++ b/startup_scripts/450_circuits.py
@@ -1,7 +1,12 @@
 import sys
 
 from circuits.models import Circuit, CircuitType, Provider
-from startup_script_utils import load_yaml, pop_custom_fields, set_custom_fields_values
+from startup_script_utils import (
+    load_yaml,
+    pop_custom_fields,
+    set_custom_fields_values,
+    split_params,
+)
 from tenancy.models import Tenant
 
 circuits = load_yaml("/opt/netbox/initializers/circuits.yml")
@@ -9,8 +14,8 @@
 if circuits is None:
     sys.exit()
 
+match_params = ["cid", "provider", "type"]
 required_assocs = {"provider": (Provider, "name"), "type": (CircuitType, "name")}
-
 optional_assocs = {"tenant": (Tenant, "name")}
 
 for params in circuits:
@@ -29,9 +34,10 @@
 
             params[assoc] = model.objects.get(**query)
 
-    circuit, created = Circuit.objects.get_or_create(**params)
+    matching_params, defaults = split_params(params, match_params)
+    circuit, created = Circuit.objects.get_or_create(**matching_params, defaults=defaults)
 
     if created:
-        set_custom_fields_values(circuit, custom_field_data)
-
         print("⚡ Created Circuit", circuit.cid)
+
+    set_custom_fields_values(circuit, custom_field_data)
diff --git a/startup_scripts/startup_script_utils/__init__.py b/startup_scripts/startup_script_utils/__init__.py
index 290b87b4f..4c25c6bee 100644
--- a/startup_scripts/startup_script_utils/__init__.py
+++ b/startup_scripts/startup_script_utils/__init__.py
@@ -1,2 +1,3 @@
 from .custom_fields import pop_custom_fields, set_custom_fields_values
 from .load_yaml import load_yaml
+from .utils import split_params
diff --git a/startup_scripts/startup_script_utils/custom_fields.py b/startup_scripts/startup_script_utils/custom_fields.py
index c00097079..74e8a2501 100644
--- a/startup_scripts/startup_script_utils/custom_fields.py
+++ b/startup_scripts/startup_script_utils/custom_fields.py
@@ -1,9 +1,38 @@
+from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import ObjectDoesNotExist
+from extras.models import CustomField
+
+
 def set_custom_fields_values(entity, custom_field_data):
     if not custom_field_data:
         return
 
-    entity.custom_field_data = custom_field_data
-    return entity.save()
+    missing_cfs = []
+    save = False
+    for key, value in custom_field_data.items():
+        try:
+            cf = CustomField.objects.get(name=key)
+        except ObjectDoesNotExist:
+            missing_cfs.append(key)
+        else:
+            ct = ContentType.objects.get_for_model(entity)
+            if ct not in cf.content_types.all():
+                print(
+                    f"⚠️ Custom field {key} is not enabled for {entity}'s model!"
+                    "Please check the 'on_objects' for that custom field in custom_fields.yml"
+                )
+            elif key not in entity.custom_field_data:
+                entity.custom_field_data[key] = value
+                save = True
+
+    if missing_cfs:
+        raise Exception(
+            f"⚠️ Custom field(s) '{missing_cfs}' requested for {entity} but not found in Netbox!"
+            "Please chceck the custom_fields.yml"
+        )
+
+    if save:
+        entity.save()
 
 
 def pop_custom_fields(params):
diff --git a/startup_scripts/startup_script_utils/utils.py b/startup_scripts/startup_script_utils/utils.py
new file mode 100644
index 000000000..e31f796f5
--- /dev/null
+++ b/startup_scripts/startup_script_utils/utils.py
@@ -0,0 +1,15 @@
+from typing import Tuple
+
+
+def split_params(params: dict, unique_params: list = None) -> Tuple[dict, dict]:
+    """Split params dict into dict with matching params and a dict with default values"""
+
+    if unique_params is None:
+        unique_params = ["name", "slug"]
+
+    matching_params = {}
+    for unique_param in unique_params:
+        param = params.pop(unique_param, None)
+        if param:
+            matching_params[unique_param] = param
+    return matching_params, params