diff --git a/mnemo_cards_backend/lib/api/v2/admin_cards_api_v2.dart b/mnemo_cards_backend/lib/api/v2/admin_cards_api_v2.dart
index 8585da4..942b91b 100644
--- a/mnemo_cards_backend/lib/api/v2/admin_cards_api_v2.dart
+++ b/mnemo_cards_backend/lib/api/v2/admin_cards_api_v2.dart
@@ -27,12 +27,25 @@ class AdminCardsApiV2 {
   AdminCardsApiV2(this._db, this._minioService);
 
   /// Validates if a string is a valid UUID (object ID in MinIO)
+  /// Supports UUID with optional file extension (e.g., .mp3, .wav)
   bool _isValidUuid(String value) {
-    final uuidRegex = RegExp(
-      r'^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$',
+    final trimmed = value.trim();
+    // UUID with optional extension: UUID followed by optional .extension
+    final uuidWithExtensionRegex = RegExp(
+      r'^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}(\.[a-z0-9]+)?$',
       caseSensitive: false,
     );
-    return uuidRegex.hasMatch(value.trim());
+    return uuidWithExtensionRegex.hasMatch(trimmed);
+  }
+
+  /// Extracts UUID from a string that may contain extension
+  /// Returns the full string (UUID + extension) if valid, or null
+  String? _extractObjectId(String value) {
+    final trimmed = value.trim();
+    if (_isValidUuid(trimmed)) {
+      return trimmed;
+    }
+    return null;
   }
 
   Future<String> _normalizeCardImageForDb({
@@ -876,7 +889,7 @@ class AdminCardsApiV2 {
       final voices = await _db.packDao.getCardVoices(cardId);
       final voicesDto = await Future.wait(
         voices.map((voice) async {
-          // Generate presigned URL if voiceUrl is a UUID (object ID)
+          // Generate presigned URL if voiceUrl is a UUID (object ID) with optional extension
           if (_isValidUuid(voice.voiceUrl)) {
             final presignedUrl = await _minioService.getPresignedUrl(
               bucket: MinioConfig.voiceAudioBucket,
@@ -945,15 +958,16 @@ class AdminCardsApiV2 {
         );
       }
 
-      // Validate that voiceUrl is a UUID (object ID from MinIO)
-      if (!_isValidUuid(requestDto.voiceUrl)) {
+      // Validate that voiceUrl is a UUID (object ID from MinIO) with optional extension
+      final objectId = _extractObjectId(requestDto.voiceUrl);
+      if (objectId == null) {
         return _json(
           ErrorResponse(
             error: 'Validation error',
             message: 'Invalid object ID format',
             field: 'voiceUrl',
             details:
-                'The provided voice URL must be a valid UUID (object ID from MinIO).',
+                'The provided voice URL must be a valid UUID (object ID from MinIO), optionally with file extension (e.g., .mp3).',
           ).toJson(),
           statusCode: 400,
         );
@@ -973,9 +987,6 @@ class AdminCardsApiV2 {
         );
       }
 
-      // Use the object ID directly
-      final objectId = requestDto.voiceUrl;
-
       // Create voice record with object ID
       print(
         '🔍 addCardVoice: Creating voice record with objectId $objectId for card $cardId',