diff --git a/src/lithic/types/transaction.py b/src/lithic/types/transaction.py
index 4b824902..080f1d6b 100644
--- a/src/lithic/types/transaction.py
+++ b/src/lithic/types/transaction.py
@@ -397,11 +397,42 @@ class EventNetworkInfoMastercard(BaseModel):
     only.
     """
 
+    original_banknet_reference_number: Optional[str] = None
+    """[Available on January 28th] Identifier assigned by Mastercard.
+
+    Matches the `banknet_reference_number` of a prior related event. May be
+    populated in authorization reversals, incremental authorizations (authorization
+    requests that augment a previously authorized amount), automated fuel dispenser
+    authorization advices and clearings, and financial authorizations. If the
+    original banknet reference number contains all zeroes, then no actual reference
+    number could be found by the network or acquirer. If Mastercard converts a
+    transaction from dual-message to single-message, such as for certain ATM
+    transactions, it will populate the original banknet reference number in the
+    resulting financial authorization with the banknet reference number of the
+    initial authorization, which Lithic does not receive.
+    """
+
+    original_switch_serial_number: Optional[str] = None
+    """[Available on January 28th] Identifier assigned by Mastercard.
+
+    Matches the `switch_serial_number` of a prior related event. May be populated in
+    returns and return reversals. Applicable to single-message transactions only.
+    """
+
 
 class EventNetworkInfoVisa(BaseModel):
     transaction_id: Optional[str] = None
     """Identifier assigned by Visa."""
 
+    original_transaction_id: Optional[str] = None
+    """[Available on January 28th] Identifier assigned by Visa.
+
+    Matches the `transaction_id` of a prior related event. May be populated in
+    incremental authorizations (authorization requests that augment a previously
+    authorized amount), authorization advices, financial authorizations, and
+    clearings.
+    """
+
 
 class EventNetworkInfo(BaseModel):
     acquirer: Optional[EventNetworkInfoAcquirer] = None
@@ -563,7 +594,9 @@ class Event(BaseModel):
     within the same transaction lifecycle and can be used to locate a particular
     transaction, such as during processing of disputes. Not all fields are available
     in all events, and the presence of these fields is dependent on the card network
-    and the event type.
+    and the event type. If the field is populated by the network, we will pass it
+    through as is unless otherwise specified. Please consult the official network
+    documentation for more details about these fields and how to use them.
     """
 
     result: Literal[