diff --git a/packages/backend/src/usagers/controllers/usagers.controller.ts b/packages/backend/src/usagers/controllers/usagers.controller.ts
index 1799470fb5..19e95d07c2 100644
--- a/packages/backend/src/usagers/controllers/usagers.controller.ts
+++ b/packages/backend/src/usagers/controllers/usagers.controller.ts
@@ -126,7 +126,7 @@ export class UsagersController {
       "telephone" | "email" | "contactByPhone"
     > = {
       telephone: {
-        countryCode: contactDetails.telephone.countryCode,
+        countryCode: contactDetails?.telephone?.countryCode ?? "fr",
         numero: getPhoneString(contactDetails.telephone).replace(/\s+/g, ""),
       },
       contactByPhone: contactDetails.contactByPhone,
diff --git a/packages/backend/src/usagers/services/tests/usagers.service.spec.ts b/packages/backend/src/usagers/services/tests/usagers.service.spec.ts
index 91cbe0db22..9b5c7e3fdc 100644
--- a/packages/backend/src/usagers/services/tests/usagers.service.spec.ts
+++ b/packages/backend/src/usagers/services/tests/usagers.service.spec.ts
@@ -24,6 +24,10 @@ describe("UsagersService", () => {
   fakeUsagerDto.dateNaissance = new Date();
   fakeUsagerDto.villeNaissance = "Paris";
   fakeUsagerDto.email = "chips@gmail.com";
+  fakeUsagerDto.telephone = {
+    countryCode: "fr",
+    numero: null,
+  };
 
   let context: AppTestContext;
 
diff --git a/packages/backend/src/usagers/services/usagers.service.ts b/packages/backend/src/usagers/services/usagers.service.ts
index fa70ee23e8..8ec2ad6442 100644
--- a/packages/backend/src/usagers/services/usagers.service.ts
+++ b/packages/backend/src/usagers/services/usagers.service.ts
@@ -48,7 +48,7 @@ export class UsagersService {
     usager.customRef = `${usager.ref}`;
 
     usager.telephone = {
-      countryCode: usagerDto.telephone.countryCode,
+      countryCode: usagerDto?.telephone?.countryCode ?? "fr",
       numero: getPhoneString(usagerDto.telephone).replace(/\s+/g, ""),
     };