diff --git a/src/main/java/life/mosu/mosuserver/application/application/ApplicationContext.java b/src/main/java/life/mosu/mosuserver/application/application/ApplicationContext.java
index d27684f8..03b731bc 100644
--- a/src/main/java/life/mosu/mosuserver/application/application/ApplicationContext.java
+++ b/src/main/java/life/mosu/mosuserver/application/application/ApplicationContext.java
@@ -53,7 +53,7 @@ public ApplicationContext fetchPayments(Function<List<Long>, List<PaymentJpaEnti
         List<Long> examApplicationIds = this.examApplications.stream()
                 .map(ExamApplicationJpaEntity::getId).toList();
         Map<Long, PaymentJpaEntity> newPaymentMap = fetcher.apply(examApplicationIds).stream()
-                .filter(payment -> payment.getPaymentStatus() == PaymentStatus.DONE)
+                .filter(payment -> payment.getPaymentStatus().equals(PaymentStatus.DONE))
                 .collect(Collectors.toMap(
                         PaymentJpaEntity::getExamApplicationId,
                         Function.identity()));
diff --git a/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java b/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java
index 22359888..42334e2f 100644
--- a/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java
+++ b/src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java
@@ -84,5 +84,4 @@ public List<ApplicationResponse> getApplications(Long userId) {
                 .fetchPayments(paymentJpaRepository::findByExamApplicationIdIn)
                 .assemble();
     }
-}
-
+}
\ No newline at end of file
diff --git a/src/main/java/life/mosu/mosuserver/application/user/MyUserService.java b/src/main/java/life/mosu/mosuserver/application/user/MyUserService.java
index ed982a51..42588f50 100644
--- a/src/main/java/life/mosu/mosuserver/application/user/MyUserService.java
+++ b/src/main/java/life/mosu/mosuserver/application/user/MyUserService.java
@@ -8,10 +8,13 @@
 import life.mosu.mosuserver.global.exception.ErrorCode;
 import life.mosu.mosuserver.presentation.user.dto.ChangePasswordRequest;
 import life.mosu.mosuserver.presentation.user.dto.ChangePasswordResponse;
+import life.mosu.mosuserver.presentation.user.dto.FindLoginIdRequest;
+import life.mosu.mosuserver.presentation.user.dto.FindLoginIdResponse;
 import life.mosu.mosuserver.presentation.user.dto.FindPasswordRequest;
 import lombok.RequiredArgsConstructor;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
 @Service
@@ -31,12 +34,23 @@ public ChangePasswordResponse changePassword(Long userId, ChangePasswordRequest
         return ChangePasswordResponse.from(Boolean.TRUE);
     }
 
-    @Transactional(readOnly = true)
+    @Transactional(readOnly = true, propagation = Propagation.SUPPORTS)
+    public FindLoginIdResponse findLoginId(FindLoginIdRequest request) {
+        UserJpaEntity user = userJpaRepository.findByNameAndPhoneNumber(request.name(),
+                        request.phoneNumber())
+                .orElseThrow(() -> new CustomRuntimeException(ErrorCode.NOT_FOUND_LOGIN_ID));
+
+        return FindLoginIdResponse.from(user.getLoginId());
+
+    }
+
+    @Transactional(readOnly = true, propagation = Propagation.SUPPORTS)
     public void findPassword(Long userId, FindPasswordRequest request) {
         UserJpaEntity user = userJpaRepository.findById(userId)
                 .orElseThrow(() -> new CustomRuntimeException(ErrorCode.USER_NOT_FOUND));
 
-        if (user.getName() != request.name() || user.getLoginId() != request.loginId()) {
+        if (!user.getName().equals(request.name()) || !user.getLoginId()
+                .equals(request.loginId())) {
             throw new CustomRuntimeException(ErrorCode.USER_INFO_INVALID);
         }
     }
diff --git a/src/main/java/life/mosu/mosuserver/domain/user/UserJpaRepository.java b/src/main/java/life/mosu/mosuserver/domain/user/UserJpaRepository.java
index 7e81de04..975bacad 100644
--- a/src/main/java/life/mosu/mosuserver/domain/user/UserJpaRepository.java
+++ b/src/main/java/life/mosu/mosuserver/domain/user/UserJpaRepository.java
@@ -1,11 +1,14 @@
 package life.mosu.mosuserver.domain.user;
 
-import org.springframework.data.jpa.repository.JpaRepository;
-
 import java.util.Optional;
+import org.springframework.data.jpa.repository.JpaRepository;
 
 public interface UserJpaRepository extends JpaRepository<UserJpaEntity, Long> {
+
     Optional<UserJpaEntity> findByLoginId(String loginId);
 
     boolean existsByLoginId(String loginId);
+
+
+    Optional<UserJpaEntity> findByNameAndPhoneNumber(String name, String phoneNumber);
 }
diff --git a/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java b/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java
index e8364b84..2cec1ae5 100644
--- a/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java
+++ b/src/main/java/life/mosu/mosuserver/global/exception/ErrorCode.java
@@ -116,7 +116,11 @@ public enum ErrorCode {
     BANNER_DELETE_FAILURE(HttpStatus.CONFLICT, "배너를 삭제하는 것에 실패하였습니다."),
     EXCEL_DATA_EMPTY(HttpStatus.NOT_FOUND, "엑셀 데이터가 없습니다."),
     EXCEL_DOWNLOAD_FAILURE(HttpStatus.CONFLICT, "엑셀 다운로드 중 문제가 발생했습니다."),
-    CACHE_UPDATE_FAIL(HttpStatus.CONFLICT, "캐시 업데이트에 실패하였습니다.");
+    CACHE_UPDATE_FAIL(HttpStatus.CONFLICT, "캐시 업데이트에 실패하였습니다."),
+
+    // ID 찾기 관련
+    NOT_FOUND_LOGIN_ID(HttpStatus.NOT_FOUND, "해당 아이디를 찾을 수 없습니다.");
+
     private final HttpStatus status;
     private final String message;
 
diff --git a/src/main/java/life/mosu/mosuserver/presentation/user/MyUserController.java b/src/main/java/life/mosu/mosuserver/presentation/user/MyUserController.java
index 1a95c35f..9c81bfcd 100644
--- a/src/main/java/life/mosu/mosuserver/presentation/user/MyUserController.java
+++ b/src/main/java/life/mosu/mosuserver/presentation/user/MyUserController.java
@@ -6,8 +6,8 @@
 import life.mosu.mosuserver.global.util.ApiResponseWrapper;
 import life.mosu.mosuserver.presentation.user.dto.ChangePasswordRequest;
 import life.mosu.mosuserver.presentation.user.dto.ChangePasswordResponse;
-import life.mosu.mosuserver.presentation.user.dto.FindIdRequest;
-import life.mosu.mosuserver.presentation.user.dto.FindIdResponse;
+import life.mosu.mosuserver.presentation.user.dto.FindLoginIdRequest;
+import life.mosu.mosuserver.presentation.user.dto.FindLoginIdResponse;
 import life.mosu.mosuserver.presentation.user.dto.FindPasswordRequest;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
@@ -25,11 +25,13 @@ public class MyUserController implements MyUserControllerDocs {
     private final MyUserService myUserService;
 
     @PostMapping("/find-id")
-    public ResponseEntity<ApiResponseWrapper<FindIdResponse>> findId(
-            @RequestBody @Valid FindIdRequest request
+    public ResponseEntity<ApiResponseWrapper<FindLoginIdResponse>> findLoginId(
+            @RequestBody @Valid FindLoginIdRequest request
     ) {
+        FindLoginIdResponse response = myUserService.findLoginId(request);
 
-        return ResponseEntity.ok(ApiResponseWrapper.success(HttpStatus.OK, "아이디 찾기 요청 성공", null));
+        return ResponseEntity.ok(
+                ApiResponseWrapper.success(HttpStatus.OK, "아이디 찾기 요청 성공", response));
     }
 
     @PostMapping("/find-password")
diff --git a/src/main/java/life/mosu/mosuserver/presentation/user/UserController.java b/src/main/java/life/mosu/mosuserver/presentation/user/UserController.java
index 4249d48d..d8fb3aa3 100644
--- a/src/main/java/life/mosu/mosuserver/presentation/user/UserController.java
+++ b/src/main/java/life/mosu/mosuserver/presentation/user/UserController.java
@@ -1,6 +1,7 @@
 package life.mosu.mosuserver.presentation.user;
 
 import life.mosu.mosuserver.application.user.UserService;
+import life.mosu.mosuserver.global.annotation.UserId;
 import life.mosu.mosuserver.global.util.ApiResponseWrapper;
 import life.mosu.mosuserver.presentation.user.dto.CustomerKeyResponse;
 import life.mosu.mosuserver.presentation.user.dto.IsLoginIdAvailableResponse;
@@ -21,7 +22,7 @@ public class UserController implements UserControllerDocs {
 
     @GetMapping("/customer-key")
     public ResponseEntity<ApiResponseWrapper<CustomerKeyResponse>> getCustomerKey(
-            @RequestParam Long userId
+            @UserId final Long userId
     ) {
         String customerKey = userService.getCustomerKey(userId);
 
diff --git a/src/main/java/life/mosu/mosuserver/presentation/user/UserControllerDocs.java b/src/main/java/life/mosu/mosuserver/presentation/user/UserControllerDocs.java
index e478df1c..6b654dc4 100644
--- a/src/main/java/life/mosu/mosuserver/presentation/user/UserControllerDocs.java
+++ b/src/main/java/life/mosu/mosuserver/presentation/user/UserControllerDocs.java
@@ -7,6 +7,7 @@
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import life.mosu.mosuserver.global.annotation.UserId;
 import life.mosu.mosuserver.global.util.ApiResponseWrapper;
 import life.mosu.mosuserver.presentation.user.dto.CustomerKeyResponse;
 import life.mosu.mosuserver.presentation.user.dto.IsLoginIdAvailableResponse;
@@ -25,7 +26,7 @@ public interface UserControllerDocs {
             @ApiResponse(responseCode = "500", description = "서버 내부 오류")
     })
     public ResponseEntity<ApiResponseWrapper<CustomerKeyResponse>> getCustomerKey(
-            @RequestParam Long userId
+            @UserId final Long userId
     );
 
     @Operation(summary = "로그인 ID 중복 확인", description = "회원가입 시 사용할 로그인 ID의 중복 여부를 확인합니다.")
diff --git a/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindIdRequest.java b/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindIdRequest.java
deleted file mode 100644
index 2b655038..00000000
--- a/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindIdRequest.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package life.mosu.mosuserver.presentation.user.dto;
-
-public record FindIdRequest (
-        String name,
-        String p
-) {
-
-}
diff --git a/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindIdResponse.java b/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindIdResponse.java
deleted file mode 100644
index 53006a1a..00000000
--- a/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindIdResponse.java
+++ /dev/null
@@ -1,6 +0,0 @@
-package life.mosu.mosuserver.presentation.user.dto;
-
-public record FindIdResponse (
-        String loginId
-) {
-}
\ No newline at end of file
diff --git a/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindLoginIdRequest.java b/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindLoginIdRequest.java
new file mode 100644
index 00000000..4391cd31
--- /dev/null
+++ b/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindLoginIdRequest.java
@@ -0,0 +1,11 @@
+package life.mosu.mosuserver.presentation.user.dto;
+
+import life.mosu.mosuserver.global.annotation.PhoneNumberPattern;
+
+public record FindLoginIdRequest(
+        String name,
+        @PhoneNumberPattern
+        String phoneNumber
+) {
+
+}
diff --git a/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindLoginIdResponse.java b/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindLoginIdResponse.java
new file mode 100644
index 00000000..8ef499ba
--- /dev/null
+++ b/src/main/java/life/mosu/mosuserver/presentation/user/dto/FindLoginIdResponse.java
@@ -0,0 +1,10 @@
+package life.mosu.mosuserver.presentation.user.dto;
+
+public record FindLoginIdResponse(
+        String loginId
+) {
+
+    public static FindLoginIdResponse from(String loginId) {
+        return new FindLoginIdResponse(loginId);
+    }
+}
\ No newline at end of file