diff --git a/web3-credential-server/build/tmp/compileJava/previous-compilation-data.bin b/web3-credential-server/build/tmp/compileJava/previous-compilation-data.bin
index 97c8c73..1bd709b 100644
Binary files a/web3-credential-server/build/tmp/compileJava/previous-compilation-data.bin and b/web3-credential-server/build/tmp/compileJava/previous-compilation-data.bin differ
diff --git a/web3-credential-server/src/main/java/web3/s3Storage/controller/S3StorageController.java b/web3-credential-server/src/main/java/web3/s3Storage/controller/S3StorageController.java
index 040c7d7..c972c36 100644
--- a/web3-credential-server/src/main/java/web3/s3Storage/controller/S3StorageController.java
+++ b/web3-credential-server/src/main/java/web3/s3Storage/controller/S3StorageController.java
@@ -44,13 +44,9 @@ public ResponseEntity<String> uploadPdf(
             @Parameter(description = "pdf 키값",required = true)
             @RequestParam String pdfKey) {
         Wallet wallet = walletService.getWalletById(walletId).orElseThrow(()-> new EntityNotFoundException("Wallet does not exist"));
-        try {
-            String pdfUrl = s3StorageService.uploadPdf(file, wallet,pdfInfo,pdfKey);
-            return ResponseEntity.ok(pdfUrl);
-        } catch (IOException e) {
-            e.printStackTrace();
-            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("Failed to upload pdf: " + e.getMessage());
-        }
+        String pdfUrl = s3StorageService.uploadPdf(file, wallet,pdfInfo,pdfKey);
+        return ResponseEntity.ok(pdfUrl);
+
     }
 
 
diff --git a/web3-credential-server/src/main/java/web3/s3Storage/service/S3StorageService.java b/web3-credential-server/src/main/java/web3/s3Storage/service/S3StorageService.java
index 85f147f..8bd4ef9 100644
--- a/web3-credential-server/src/main/java/web3/s3Storage/service/S3StorageService.java
+++ b/web3-credential-server/src/main/java/web3/s3Storage/service/S3StorageService.java
@@ -36,47 +36,39 @@ public S3StorageService(S3Properties s3Properties, WalletRepository walletReposi
         this.walletRepository = walletRepository;
     }
 
-    public String uploadPdf(MultipartFile file, Wallet wallet,String pdfInfo,String pdfKey) throws IOException {
+    @Transactional
+    public String uploadPdf(MultipartFile file, Wallet wallet, String pdfInfo, String pdfKey) {
         String fileName;
         byte[] result;
         HashMap<String, String> metadata = new HashMap<>();
         int nowPage = 1;
 
-        //첫 등록일때 => 생성해줘야함
-        if (wallet.getPdfUrl() == null){
-            fileName = (file.getSize() > 0) ? getFileName(wallet): getEmptyFilename(wallet);
-
-            // PDF 파일 확장자 검증
-            //validatePdfFile(fileName);
-            result = (file.getSize() > 0) ? file.getBytes():createEmptyPdf();
-
-        }
-        else{
-            //이미 있을시 -> pdf 병합
+        // 첫 등록일 때 => 생성해줘야 함
+        if (wallet.getPdfUrl() == null) {
+            fileName = (file.getSize() > 0) ? getFileName(wallet) : getEmptyFilename(wallet);
+            result = (file.getSize() > 0) ? getFileBytes(file) : createEmptyPdf();
+        } else {
+            // 이미 있을 시 -> PDF 병합
             String destination = wallet.getPdfUrl();
             fileName = extractKeyFromUrl(destination);
 
-            byte[] first = getPdf(destination).readAllBytes();//원래 파일
-            byte[] second = (file.getSize() > 0) ? file.getBytes() : createEmptyPdf(); //뒤에 들어온 파일
+            byte[] first = new byte[0]; // 원래 파일
+            first = getBytes(destination);
+            byte[] second = (file.getSize() > 0) ? getFileBytes(file) : createEmptyPdf(); // 뒤에 들어온 파일
 
-            nowPage = getPdfPageCount(first)+1;
+            nowPage = getPdfPageCount(first) + 1;
             result = mergePdfs(first, second);
 
-            metadata= decodeMetadata(getPdfMetadata(fileName));
+            metadata = decodeMetadata(getPdfMetadata(fileName));
         }
 
         String page = "page-" + nowPage; // 키 설정
         String value = pdfInfo + ":" + pdfKey;
-        metadata.put(page,value); // 키-값 쌍으로 추가
+        metadata.put(page, value); // 키-값 쌍으로 추가
 
         log.info("metadata = {}", metadata);
 
-        try {
-            uploadToS3(fileName, metadata, result);
-
-        } catch (S3Exception e) {
-            throw new IOException("Failed to upload pdf to S3: " + e.getMessage());
-        }
+        uploadPdf(fileName, metadata, result);
 
         wallet.updatePdfUrl(getpdfUrl(fileName));
         walletRepository.saveAndFlush(wallet);
@@ -84,6 +76,35 @@ public String uploadPdf(MultipartFile file, Wallet wallet,String pdfInfo,String
         return getpdfUrl(fileName);
     }
 
+
+
+    private byte[] getBytes(String destination) {
+        byte[] first;
+        try {
+            first = getPdf(destination).readAllBytes();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        return first;
+    }
+
+    // 파일 바이트 배열을 가져오는 메서드 추가 (오류 처리 포함)
+    private byte[] getFileBytes(MultipartFile file) {
+        try {
+            return file.getBytes();
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to get file bytes: " + e.getMessage(), e);
+        }
+    }
+
+    private void uploadPdf(String fileName, HashMap<String, String> metadata, byte[] result) {
+        try {
+            uploadToS3(fileName, metadata, result);
+        } catch (S3Exception e) {
+            throw new RuntimeException("Failed to upload pdf to S3: " + e.getMessage(), e);
+        }
+    }
+
     private void uploadToS3(String fileName, HashMap<String, String> metadata, byte[] result) {
 
         HashMap<String, String> encodedMetadata = new HashMap<>();
@@ -95,6 +116,7 @@ private void uploadToS3(String fileName, HashMap<String, String> metadata, byte[
         PutObjectRequest putRequest = PutObjectRequest.builder()
                 .bucket(s3Properties.getS3BucketName())
                 .key(fileName)
+
                 .contentType("application/pdf")
                 .metadata(encodedMetadata)
                 .build();
@@ -111,7 +133,7 @@ private static String getEmptyFilename(Wallet wallet) {
         return wallet.getAddress() + "_" + System.currentTimeMillis() + "_" + "empty.pdf";
     }
 
-    public byte[] mergePdfs(byte[] pdf1, byte[] pdf2) throws IOException {
+    public byte[] mergePdfs(byte[] pdf1, byte[] pdf2){
         PDFMergerUtility merger = new PDFMergerUtility();
 
         ByteArrayInputStream inputStream1 = new ByteArrayInputStream(pdf1);
@@ -122,17 +144,23 @@ public byte[] mergePdfs(byte[] pdf1, byte[] pdf2) throws IOException {
 
         ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
         merger.setDestinationStream(outputStream);
-        merger.mergeDocuments(null);
+        try {
+            merger.mergeDocuments(null);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
 
         return outputStream.toByteArray();
     }
 
-    private byte[] createEmptyPdf() throws IOException {
+    private byte[] createEmptyPdf(){
         try (PDDocument document = new PDDocument()) {
             document.addPage(new PDPage()); // 빈 페이지 추가
             ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
             document.save(outputStream);
             return outputStream.toByteArray();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
         }
     }
 
@@ -316,9 +344,11 @@ public String getPdfKeyForPage(String pdfUrl, int pageNumber) {
 
 
 
-    public int getPdfPageCount(byte[] pdfBytes) throws IOException {
+    public int getPdfPageCount(byte[] pdfBytes){
         try (PDDocument document = PDDocument.load(pdfBytes)) {
             return document.getNumberOfPages();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
         }
     }