diff --git a/src/main/java/yonseigolf/server/apply/service/ApplyService.java b/src/main/java/yonseigolf/server/apply/service/ApplyService.java
index d9db6b0..8c925be 100644
--- a/src/main/java/yonseigolf/server/apply/service/ApplyService.java
+++ b/src/main/java/yonseigolf/server/apply/service/ApplyService.java
@@ -68,18 +68,6 @@ public void updatePass(Long id, UpdatePassRequest request) {
         findById(id).updatePass(request);
     }
 
-//    @Transactional
-//    public void updateDocumentPass(Long id, Boolean updatePass) {
-//
-//        findById(id).updateDocumentPass(updatePass);
-//    }
-//
-//    @Transactional
-//    public void updateFinalPass(Long id, Boolean finalPass) {
-//
-//        findById(id).updateFinalPass(finalPass);
-//    }
-
     @Transactional
     public void updateInterviewTime(Long id, LocalDateTime time) {
 
@@ -88,7 +76,7 @@ public void updateInterviewTime(Long id, LocalDateTime time) {
 
     public void sendEmailNotification(boolean isDocumentPass, Boolean isFinalPass) {
 
-        final NotificationType type = getNotificationType(isDocumentPass, isFinalPass);
+        final NotificationType type = NotificationType.decideNotificationType(isDocumentPass, isFinalPass);
         final String subject = "안녕하세요. 연세대학교 골프동아리 결과 메일입니다.";
 
         findApplicationsByPassFail(isDocumentPass, isFinalPass)
@@ -98,17 +86,6 @@ public void sendEmailNotification(boolean isDocumentPass, Boolean isFinalPass) {
                 });
     }
 
-    private NotificationType getNotificationType(boolean isDocumentPass, Boolean isFinalPass) {
-
-        if (isDocumentPass && isFinalPass == null) {
-            return NotificationType.DOCUMENT_PASS;
-        }
-        if (isDocumentPass && isFinalPass) {
-            return NotificationType.FINAL_PASS;
-        }
-        return NotificationType.FAIL;
-    }
-
     private List<Application> findApplicationsByPassFail(Boolean docuemntPass, Boolean finalPass) {
 
         return applicationRepository.findApplicationsForEmail(docuemntPass, finalPass);
diff --git a/src/main/java/yonseigolf/server/board/entity/Board.java b/src/main/java/yonseigolf/server/board/entity/Board.java
index 5f7d53d..97dbfe5 100644
--- a/src/main/java/yonseigolf/server/board/entity/Board.java
+++ b/src/main/java/yonseigolf/server/board/entity/Board.java
@@ -53,7 +53,7 @@ public static Board createBoardForForeignKey(long boardId) {
 
     public void updateBoard(UpdateBoardRequest request) {
 
-        if (this.deleted == true) {
+        if (this.deleted) {
             throw new DeletedBoardException("이미 삭제된 게시글 입니다.");
         }
 
@@ -64,10 +64,17 @@ public void updateBoard(UpdateBoardRequest request) {
 
     public void deleteBoard() {
 
-        if (this.deleted == true) {
+        if (this.deleted) {
             throw new DeletedBoardException("이미 삭제된 게시글 입니다.");
         }
 
         this.deleted = true;
     }
+
+    public void checkOwner(Long userId) {
+
+        if(!this.writer.checkOwner(userId)){
+            throw new IllegalArgumentException("작성자만 게시글을 수정/삭제 할 수 있습니다.");
+        }
+    }
 }
diff --git a/src/main/java/yonseigolf/server/board/entity/Reply.java b/src/main/java/yonseigolf/server/board/entity/Reply.java
index 6f23358..a57da3c 100644
--- a/src/main/java/yonseigolf/server/board/entity/Reply.java
+++ b/src/main/java/yonseigolf/server/board/entity/Reply.java
@@ -37,4 +37,11 @@ public static Reply createReplyForPost(long writerId, long boardId, PostReplyReq
                 .user(User.createUserForForeignKey(writerId))
                 .build();
     }
+
+    public void checkOwner(Long userId) {
+
+        if (!user.checkOwner(userId)) {
+            throw new IllegalArgumentException("작성자가 아닙니다.");
+        }
+    }
 }
diff --git a/src/main/java/yonseigolf/server/board/service/BoardService.java b/src/main/java/yonseigolf/server/board/service/BoardService.java
index e35d63d..d0ae63b 100644
--- a/src/main/java/yonseigolf/server/board/service/BoardService.java
+++ b/src/main/java/yonseigolf/server/board/service/BoardService.java
@@ -45,25 +45,19 @@ public void postBoard(CreateBoardRequest createBoardRequest, long userId) {
         boardRepository.save(Board.createBoardForPost(createBoardRequest, userId));
     }
 
-    // TODO: 작성자와 수정하려는 사람이 같은 지 확인
     @Transactional
     public void updateBoard(Long boardId, UpdateBoardRequest createBoardRequest, Long userId) {
 
         Board board = findById(boardId);
-        if (board.getWriter().getId() != userId) {
-            throw new IllegalArgumentException("작성자와 수정하려는 사람이 다릅니다.");
-        }
+        board.checkOwner(userId);
         board.updateBoard(createBoardRequest);
     }
 
-    // TODO: 작성자와 삭제하려는 사람이 같은지 확인
     @Transactional
     public void deleteBoard(Long boardId, Long userId) {
 
         Board board = findById(boardId);
-        if (board.getWriter().getId() != userId) {
-            throw new IllegalArgumentException("작성자만 게시글을 삭제할 수 있습니다.");
-        }
+        board.checkOwner(userId);
         board.deleteBoard();
     }
 
diff --git a/src/main/java/yonseigolf/server/board/service/ReplyService.java b/src/main/java/yonseigolf/server/board/service/ReplyService.java
index 41b01c3..438b2dd 100644
--- a/src/main/java/yonseigolf/server/board/service/ReplyService.java
+++ b/src/main/java/yonseigolf/server/board/service/ReplyService.java
@@ -22,12 +22,10 @@ public void postReply(long writerId, long boardId, PostReplyRequest replyRequest
         replyRepository.save(reply);
     }
 
-    // TODO: 작성자와 삭제하려는 사람이 같은지 확인
     public void deleteReply(long replyId, long userId) {
+
         Reply reply = findReply(replyId);
-        if (reply.getUser().getId() != userId){
-            throw new IllegalArgumentException("작성자가 아닙니다.");
-        }
+        reply.checkOwner(userId);
         replyRepository.deleteById(replyId);
     }
 
diff --git a/src/main/java/yonseigolf/server/email/dto/NotificationType.java b/src/main/java/yonseigolf/server/email/dto/NotificationType.java
index ff61792..7fb9f71 100644
--- a/src/main/java/yonseigolf/server/email/dto/NotificationType.java
+++ b/src/main/java/yonseigolf/server/email/dto/NotificationType.java
@@ -34,4 +34,14 @@ public String generateMessage(String name) {
     };
 
     public abstract String generateMessage(String name);
+
+    public static NotificationType decideNotificationType(boolean isDocumentPass, Boolean isFinalPass) {
+        if (isDocumentPass && isFinalPass == null) {
+            return DOCUMENT_PASS;
+        }
+        if (isDocumentPass && isFinalPass) {
+            return FINAL_PASS;
+        }
+        return FAIL;
+    }
 }
diff --git a/src/main/java/yonseigolf/server/user/controller/UserController.java b/src/main/java/yonseigolf/server/user/controller/UserController.java
index e381654..47ab769 100644
--- a/src/main/java/yonseigolf/server/user/controller/UserController.java
+++ b/src/main/java/yonseigolf/server/user/controller/UserController.java
@@ -67,18 +67,17 @@ public ResponseEntity<CustomResponse<JwtTokenResponse>> kakaoLogin(@RequestBody
                 );
     }
 
-    // TODO: 세션이 아닌 JWT Token으로부터 userId 가져와야 함, user의 refresh token이 없거나 만료된 경우 재발급
     @PostMapping("/users/signIn")
     public ResponseEntity<CustomResponse<JwtTokenResponse>> signIn(@RequestAttribute(required = false) Long kakaoId, HttpServletResponse response) {
-        System.out.println(kakaoId);
+
         LoggedInUser loggedInUser = userService.signIn(kakaoId);
 
         // 30분 시간 제한
         Date date = new Date(new Date().getTime() + 1800000);
         String tokenReponse = jwtUtil.createToken(loggedInUser, date);
 
-        // refresh token 검증후 발급 - 2주기한
-        validateRefreshTokenAndRefresh(loggedInUser.getId(), response, loggedInUser);
+        // signIn 할 경우 로그인 진행
+        makeRefreshToken(response, loggedInUser);
 
         return ResponseEntity
                 .ok()
@@ -89,9 +88,7 @@ public ResponseEntity<CustomResponse<JwtTokenResponse>> signIn(@RequestAttribute
                 );
     }
 
-    private void validateRefreshTokenAndRefresh(Long userId, HttpServletResponse response, LoggedInUser loggedInUser) {
-        // refresh token이 없거나 만료된 경우 재발급
-        userService.validateRefreshToken(userId, jwtUtil);
+    private void makeRefreshToken(HttpServletResponse response, LoggedInUser loggedInUser) {
 
         Date expireDate = new Date(new Date().getTime() + 1209600000);
         String refreshToken = jwtUtil.createRefreshToken(loggedInUser.getId(), expireDate);
@@ -102,7 +99,7 @@ private void validateRefreshTokenAndRefresh(Long userId, HttpServletResponse res
     private void createRefreshToken(HttpServletResponse response, String refreshToken) {
         Cookie cookie = new Cookie("refreshToken", refreshToken);
         cookie.setHttpOnly(true); // HTTP Only 설정
-        cookie.setSecure(true); // Secure 설정, TODO: 배포할 땐 true로 변경
+        cookie.setSecure(true); // Secure 설정,
         cookie.setPath("/"); // 경로 설정
         cookie.setMaxAge(60 * 60 * 24 * 14); // 2주일
         response.addCookie(cookie); // 응답에 쿠키 추가
diff --git a/src/main/java/yonseigolf/server/user/entity/User.java b/src/main/java/yonseigolf/server/user/entity/User.java
index cc76d80..2a22bcb 100644
--- a/src/main/java/yonseigolf/server/user/entity/User.java
+++ b/src/main/java/yonseigolf/server/user/entity/User.java
@@ -93,4 +93,8 @@ public void invalidateRefreshToken() {
 
         this.refreshToken = null;
     }
+
+    public boolean checkOwner(Long userId) {
+        return this.id == userId;
+    }
 }
diff --git a/src/test/java/yonseigolf/server/board/service/BoardServiceTest.java b/src/test/java/yonseigolf/server/board/service/BoardServiceTest.java
index 9a0e893..3e37f96 100644
--- a/src/test/java/yonseigolf/server/board/service/BoardServiceTest.java
+++ b/src/test/java/yonseigolf/server/board/service/BoardServiceTest.java
@@ -172,7 +172,7 @@ void deleteErrorTest() {
         // when & then
         assertThatThrownBy(() -> boardService.deleteBoard(savedBoard.getId(), 2L))
                 .isInstanceOf(IllegalArgumentException.class)
-                .hasMessage("작성자만 게시글을 삭제할 수 있습니다.");
+                .hasMessage("작성자만 게시글을 수정/삭제 할 수 있습니다.");
     }
 
     @Test
@@ -219,7 +219,7 @@ void updateBoardTest() {
         // then
         assertThatThrownBy(() -> boardService.updateBoard(saved.getId(), UpdateBoardRequest.builder().build(), 2L))
                 .isInstanceOf(IllegalArgumentException.class)
-                .hasMessage("작성자와 수정하려는 사람이 다릅니다.");
+                .hasMessage("작성자만 게시글을 수정/삭제 할 수 있습니다.");
     }
 
     @Test
diff --git a/src/test/java/yonseigolf/server/board/service/ReplyServiceTest.java b/src/test/java/yonseigolf/server/board/service/ReplyServiceTest.java
index 0787e4e..ac22b2f 100644
--- a/src/test/java/yonseigolf/server/board/service/ReplyServiceTest.java
+++ b/src/test/java/yonseigolf/server/board/service/ReplyServiceTest.java
@@ -1,10 +1,10 @@
 package yonseigolf.server.board.service;
 
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.transaction.annotation.Transactional;
 import yonseigolf.server.board.dto.request.PostReplyRequest;
 import yonseigolf.server.board.entity.Board;
 import yonseigolf.server.board.entity.Category;
@@ -21,6 +21,7 @@
 import static org.assertj.core.api.AssertionsForClassTypes.assertThatThrownBy;
 import static org.junit.jupiter.api.Assertions.assertAll;
 
+@Transactional
 @SpringBootTest
 class ReplyServiceTest {
 
@@ -33,12 +34,6 @@ class ReplyServiceTest {
     @Autowired
     private UserRepository userRepository;
 
-    @BeforeEach
-    void setUp() {
-        replyRepository.deleteAll();
-        boardRepository.deleteAll();
-        userRepository.deleteAll();
-    }
     @Test
     @DisplayName("댓글 생성 테스트")
     void postReplyTest() {