diff --git a/src/main/java/life/mosu/mosuserver/application/user/UserService.java b/src/main/java/life/mosu/mosuserver/application/user/UserService.java
index ce3b0918..eefaacc2 100644
--- a/src/main/java/life/mosu/mosuserver/application/user/UserService.java
+++ b/src/main/java/life/mosu/mosuserver/application/user/UserService.java
@@ -5,6 +5,7 @@
 import life.mosu.mosuserver.domain.user.repository.UserJpaRepository;
 import life.mosu.mosuserver.global.exception.CustomRuntimeException;
 import life.mosu.mosuserver.global.exception.ErrorCode;
+import life.mosu.mosuserver.global.util.PhoneNumberUtil;
 import life.mosu.mosuserver.presentation.user.dto.response.UserInfoResponse;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -38,7 +39,8 @@ public void syncUserInfoFromProfile(UserJpaEntity user, ProfileJpaEntity profile
     }
 
     public Long saveOrGetUser(UserJpaEntity user) {
-        return userJpaRepository.findByPhoneNumber(user.getPhoneNumber())
+        return userJpaRepository.findByPhoneNumber(
+                        PhoneNumberUtil.formatGuestPhoneNumber(user.getPhoneNumber()))
                 .map(UserJpaEntity::getId)
                 .orElseGet(() -> {
                     Long userId = userJpaRepository.save(user).getId();