diff --git a/model/src/components/types.ts b/model/src/components/types.ts
index 329765230d..1dc0f2e06c 100644
--- a/model/src/components/types.ts
+++ b/model/src/components/types.ts
@@ -190,6 +190,7 @@ export interface TelephoneNumberFieldComponent extends TextFieldBase {
   type: "TelephoneNumberField";
   options: TextFieldBase["options"] & {
     customValidationMessage?: string;
+    isInternational?: boolean;
   };
 }
 
diff --git a/runner/package.json b/runner/package.json
index 559225cfc9..11821897ca 100644
--- a/runner/package.json
+++ b/runner/package.json
@@ -49,6 +49,7 @@
     "@hapi/vision": "^7.0.3",
     "@hapi/wreck": "^18.0.1",
     "@hapi/yar": "^11.0.1",
+    "@types/google-libphonenumber": "^7.4.30",
     "accept-language-parser": "1.5.0",
     "accessible-autocomplete": "^2.0.2",
     "atob": "^2.1.2",
@@ -60,6 +61,7 @@
     "config": "^3.3.7",
     "dotenv": "8.2.0",
     "expr-eval": "^2.0.2",
+    "google-libphonenumber": "^3.2.34",
     "govuk-frontend": "^4.8.0",
     "hapi-pino": "8.0.0",
     "hapi-pulse": "3.0.0",
diff --git a/runner/src/server/plugins/engine/components/TelephoneNumberField.ts b/runner/src/server/plugins/engine/components/TelephoneNumberField.ts
index 9d05afa513..59fe21b60c 100644
--- a/runner/src/server/plugins/engine/components/TelephoneNumberField.ts
+++ b/runner/src/server/plugins/engine/components/TelephoneNumberField.ts
@@ -2,7 +2,7 @@ import { TelephoneNumberFieldComponent } from "@xgovformbuilder/model";
 
 import { FormComponent } from "./FormComponent";
 import { FormModel } from "../models";
-import { addClassOptionIfNone } from "./helpers";
+import { addClassOptionIfNone, internationalPhoneValidator } from "./helpers";
 import { FormData, FormSubmissionErrors } from "../types";
 import joi, { Schema } from "joi";
 
@@ -32,6 +32,9 @@ export class TelephoneNumberField extends FormComponent {
       componentSchema = componentSchema.min(schema.min);
     }
 
+    if (options.isInternational) {
+      componentSchema = componentSchema.custom(internationalPhoneValidator);
+    }
     this.schema = componentSchema;
 
     addClassOptionIfNone(this.options, "govuk-input--width-10");
diff --git a/runner/src/server/plugins/engine/components/helpers.ts b/runner/src/server/plugins/engine/components/helpers.ts
index 77b97c0566..a268ba8e04 100644
--- a/runner/src/server/plugins/engine/components/helpers.ts
+++ b/runner/src/server/plugins/engine/components/helpers.ts
@@ -1,5 +1,8 @@
 import joi from "joi";
 import { add, startOfToday, sub } from "date-fns";
+import { PhoneNumberFormat, PhoneNumberUtil } from "google-libphonenumber";
+
+const phoneUtil = PhoneNumberUtil.getInstance();
 
 /**
  * FIXME:- this code is bonkers. buildFormSchema and buildState schema are duplicates.
@@ -117,3 +120,11 @@ export function getCustomDateValidator(
     return value;
   };
 }
+
+export function internationalPhoneValidator(
+  value: string,
+  _helpers: joi.CustomHelpers
+) {
+  const phone = phoneUtil.parseAndKeepRawInput(value);
+  return phoneUtil.format(phone, PhoneNumberFormat.INTERNATIONAL);
+}
diff --git a/yarn.lock b/yarn.lock
index cf58c7bed3..c40aef7d41 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4031,6 +4031,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/google-libphonenumber@npm:^7.4.30":
+  version: 7.4.30
+  resolution: "@types/google-libphonenumber@npm:7.4.30"
+  checksum: 09270ed030076a0e69965ad5bad564e672a110e1e83c9092f6d264c3e0355921631521cb9afd022018a51cddfd19ba52d0421f4682d7b68b836dbb52537320de
+  languageName: node
+  linkType: hard
+
 "@types/graceful-fs@npm:^4.1.2, @types/graceful-fs@npm:^4.1.3":
   version: 4.1.9
   resolution: "@types/graceful-fs@npm:4.1.9"
@@ -5127,6 +5134,7 @@ __metadata:
     "@hapi/wreck": ^18.0.1
     "@hapi/yar": ^11.0.1
     "@oclif/core": ^1.19.0
+    "@types/google-libphonenumber": ^7.4.30
     "@types/hapi": ^18.0.7
     "@types/hapi__yar": ^10.1.1
     "@types/hoek": ^4.1.4
@@ -5161,6 +5169,7 @@ __metadata:
     expr-eval: ^2.0.2
     flat: 5.0.2
     form-data: ^4.0.0
+    google-libphonenumber: ^3.2.34
     govuk-frontend: ^4.8.0
     hapi-pino: 8.0.0
     hapi-pulse: 3.0.0
@@ -11426,6 +11435,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"google-libphonenumber@npm:^3.2.34":
+  version: 3.2.34
+  resolution: "google-libphonenumber@npm:3.2.34"
+  checksum: a14579bb8d4934dc6b9cfb33f818375ccdc67be12f13f842a4c16d7c3bd8ef9f2aacc30d368770f33a97ba8674e23b318cb59f26616c7fa2ce60fae52b2f6ebf
+  languageName: node
+  linkType: hard
+
 "gopd@npm:^1.0.1":
   version: 1.0.1
   resolution: "gopd@npm:1.0.1"