diff --git a/src/main/java/com/eactive/apim/portal/apps/user/service/PortalUserAuthService.java b/src/main/java/com/eactive/apim/portal/apps/user/service/PortalUserAuthService.java
index ec03752..d62fd1c 100644
--- a/src/main/java/com/eactive/apim/portal/apps/user/service/PortalUserAuthService.java
+++ b/src/main/java/com/eactive/apim/portal/apps/user/service/PortalUserAuthService.java
@@ -102,10 +102,11 @@ public class PortalUserAuthService implements UserDetailsService {
     }
 
     public void resetPassword(String loginId, String userName, String mobileNumber) {
-        // 전화번호에서 - 제거하여 정규화
-        String normalizedMobileNumber = mobileNumber != null ? mobileNumber.replace("-", "") : null;
+        if (mobileNumber == null || !mobileNumber.matches("^\\d{2,3}-\\d{3,4}-\\d{4}$")) {
+            throw new UserNotFoundException("유효하지 않은 휴대폰 번호 형식입니다.");
+        }
 
-        PortalUser portalUser = portalUserRepository.findByLoginIdAndUserNameAndMobileNumber(loginId, userName, normalizedMobileNumber)
+        PortalUser portalUser = portalUserRepository.findByLoginIdAndUserNameAndMobileNumber(loginId, userName, mobileNumber)
                 .orElseThrow(() -> new UserNotFoundException("일치하는 사용자 정보를 찾을 수 없습니다."));
 
         String tempPassword = EncryptionUtil.generateNewPassword();