diff --git a/src/main/java/com/meetkey/server/domain/auth/service/AuthService.java b/src/main/java/com/meetkey/server/domain/auth/service/AuthService.java
index 45ffae9..a8c8572 100644
--- a/src/main/java/com/meetkey/server/domain/auth/service/AuthService.java
+++ b/src/main/java/com/meetkey/server/domain/auth/service/AuthService.java
@@ -155,7 +155,7 @@ public void withdraw(Long memberId, String refreshToken){
         log.info("해당 유저의 social ProviderId: " + socialLogin.getProviderId());
 
         member.updateMemberStatus(Status.INACTIVE); // 소프트 탈퇴 처리
-        member.updatePhoneNumber("");
+        member.updatePhoneNumber("no_use_" + memberId);
         refreshTokenRepository.delete(refreshToken);
 
         kakaoApiClient.unlink("KakaoAK "+ kakaoAdminKey, "user_id", Long.parseLong(socialLogin.getProviderId()));