diff --git a/apps/portal/src/features/get-started/components/GetStartedForm/steps/complete-account/useCompleteAccountForm.ts b/apps/portal/src/features/get-started/components/GetStartedForm/steps/complete-account/useCompleteAccountForm.ts
index c55c0aaf..9ec548c8 100644
--- a/apps/portal/src/features/get-started/components/GetStartedForm/steps/complete-account/useCompleteAccountForm.ts
+++ b/apps/portal/src/features/get-started/components/GetStartedForm/steps/complete-account/useCompleteAccountForm.ts
@@ -2,6 +2,7 @@ import { useState, useCallback } from "react";
 import { type JapanAddressFormData } from "@/features/address/components/JapanAddressForm";
 import { prepareWhmcsAddressFields } from "@customer-portal/domain/address";
 import { validatePasswordRules } from "@/features/auth/hooks/usePasswordValidation";
+import { phoneSchema } from "@customer-portal/domain/common";
 import type { AccountFormErrors } from "./types";
 
 interface FormState {
@@ -90,7 +91,14 @@ export function useCompleteAccountForm({
     const passwordError = validatePasswordRules(password);
     if (passwordError) newErrors.password = passwordError;
     if (password !== confirmPassword) newErrors.confirmPassword = "Passwords do not match";
-    if (!phone.trim()) newErrors.phone = "Phone number is required";
+    if (phone.trim()) {
+      const phoneResult = phoneSchema.safeParse(phone.trim());
+      if (!phoneResult.success) {
+        newErrors.phone = "Please enter a valid phone number";
+      }
+    } else {
+      newErrors.phone = "Phone number is required";
+    }
     if (!dateOfBirth) newErrors.dateOfBirth = "Date of birth is required";
     if (!gender) newErrors.gender = "Please select a gender";
     if (!acceptTerms) newErrors.acceptTerms = "You must accept the terms of service";
diff --git a/apps/portal/src/features/services/components/eligibility-check/steps/CompleteAccountStep.tsx b/apps/portal/src/features/services/components/eligibility-check/steps/CompleteAccountStep.tsx
index 1f248ebc..e43ca47c 100644
--- a/apps/portal/src/features/services/components/eligibility-check/steps/CompleteAccountStep.tsx
+++ b/apps/portal/src/features/services/components/eligibility-check/steps/CompleteAccountStep.tsx
@@ -15,6 +15,7 @@ import {
   validatePasswordRules,
   usePasswordValidation,
 } from "@/features/auth/hooks/usePasswordValidation";
+import { phoneSchema } from "@customer-portal/domain/common";
 import { useEligibilityCheckStore } from "../../../stores/eligibility-check.store";
 import { AccountInfoDisplay, PersonalInfoFields, PasswordSection } from "./complete-account";
 
@@ -59,7 +60,14 @@ export function CompleteAccountStep() {
     if (passwordError) errors.password = passwordError;
     if (accountData.password !== accountData.confirmPassword)
       errors.confirmPassword = "Passwords do not match";
-    if (!accountData.phone.trim()) errors.phone = "Phone number is required";
+    if (accountData.phone.trim()) {
+      const phoneResult = phoneSchema.safeParse(accountData.phone.trim());
+      if (!phoneResult.success) {
+        errors.phone = "Please enter a valid phone number";
+      }
+    } else {
+      errors.phone = "Phone number is required";
+    }
     if (!accountData.dateOfBirth) errors.dateOfBirth = "Date of birth is required";
     if (!accountData.gender) errors.gender = "Please select a gender";
     if (!accountData.acceptTerms) errors.acceptTerms = "You must accept the terms of service";