diff --git a/internal/contract/letter_outgoing_contract.go b/internal/contract/letter_outgoing_contract.go
index 1df1961..3439b90 100644
--- a/internal/contract/letter_outgoing_contract.go
+++ b/internal/contract/letter_outgoing_contract.go
@@ -43,6 +43,7 @@ type CreateOutgoingLetterAttachment struct {
 	FileURL  string `json:"file_url" validate:"required"`
 	FileName string `json:"file_name" validate:"required"`
 	FileType string `json:"file_type" validate:"required"`
+	IsFinal  bool   `json:"is_final" validate:"omitempty"`
 }
 
 type CreateOutgoingLetterRequest struct {
@@ -79,6 +80,7 @@ type OutgoingLetterAttachmentResponse struct {
 	FileName   string    `json:"file_name"`
 	FileType   string    `json:"file_type"`
 	UploadedAt time.Time `json:"uploaded_at"`
+	IsFinal    bool      `json:"is_final"`
 }
 
 type OutgoingLetterApprovalResponse struct {
diff --git a/internal/entities/letter_outgoing.go b/internal/entities/letter_outgoing.go
index 35e6fcf..756190e 100644
--- a/internal/entities/letter_outgoing.go
+++ b/internal/entities/letter_outgoing.go
@@ -76,6 +76,7 @@ type LetterOutgoingAttachment struct {
 	FileType       string     `gorm:"not null" json:"file_type"`
 	UploadedBy     *uuid.UUID `json:"uploaded_by,omitempty"`
 	UploadedAt     time.Time  `gorm:"autoCreateTime" json:"uploaded_at"`
+	IsFinal        bool       `gorm:"default:false" json:"is_final"`
 }
 
 func (LetterOutgoingAttachment) TableName() string { return "letter_outgoing_attachments" }
diff --git a/internal/service/letter_outgoing_service.go b/internal/service/letter_outgoing_service.go
index 504b741..ce3437f 100644
--- a/internal/service/letter_outgoing_service.go
+++ b/internal/service/letter_outgoing_service.go
@@ -911,11 +911,11 @@ func (s *LetterOutgoingServiceImpl) AddAttachments(ctx context.Context, letterID
 	attachments := make([]entities.LetterOutgoingAttachment, len(req.Attachments))
 	for i, a := range req.Attachments {
 		attachments[i] = entities.LetterOutgoingAttachment{
-			LetterID:   letterID,
-			FileURL:    a.FileURL,
-			FileName:   a.FileName,
-			FileType:   a.FileType,
-			UploadedBy: &userID,
+			LetterID: letterID,
+			FileURL:  a.FileURL,
+			FileName: a.FileName,
+			FileType: a.FileType,
+			IsFinal:  a.IsFinal,
 		}
 	}
 
@@ -1589,6 +1589,7 @@ func transformLetterToResponse(letter *entities.LetterOutgoing) *contract.Outgoi
 				FileName:   attachment.FileName,
 				FileType:   attachment.FileType,
 				UploadedAt: attachment.UploadedAt,
+				IsFinal:    attachment.IsFinal,
 			}
 		}
 	}
diff --git a/migrations/000045_add_is_final_to_letter_outgoing_attachments.down.sql b/migrations/000045_add_is_final_to_letter_outgoing_attachments.down.sql
new file mode 100644
index 0000000..e69de29
diff --git a/migrations/000045_add_is_final_to_letter_outgoing_attachments.up.sql b/migrations/000045_add_is_final_to_letter_outgoing_attachments.up.sql
new file mode 100644
index 0000000..cd08359
--- /dev/null
+++ b/migrations/000045_add_is_final_to_letter_outgoing_attachments.up.sql
@@ -0,0 +1,2 @@
+ALTER TABLE letter_outgoing_attachments
+    ADD COLUMN IF NOT EXISTS is_final BOOLEAN NOT NULL DEFAULT FALSE;
\ No newline at end of file