diff --git a/backend/src/func/createPayer.ts b/backend/src/func/createPayer.ts
index 3d93ff7..fee51c4 100644
--- a/backend/src/func/createPayer.ts
+++ b/backend/src/func/createPayer.ts
@@ -14,12 +14,15 @@ console.log = Debug('invoiceIssuer:func/createPayer.ts')
  */
 export default async (prisma: PrismaClient, name: string, address: string[], email: string, abn?: string) => {
 	// 验证 ABN 是否已存在
-	const existingPayer = await prisma.payer.findFirst({
-		where: {
-			payer_abn: abn
-		}
-	})
-	if (existingPayer) throw new HttpError(ErrorDescEnum.item_exists, 400, ['abn'])
+	if (abn) {
+		console.log('Checking if ABN exists:', abn)
+		const existingPayer = await prisma.payer.findFirst({
+			where: {
+				payer_abn: abn
+			}
+		})
+		if (existingPayer) throw new HttpError(ErrorDescEnum.item_exists, 400, ['abn'])
+	}
 
 	// 创建新的付款人
 	const payer = await prisma.payer.create({