diff --git a/src/AKSRT/Payment/Gateway.php b/src/AKSRT/Payment/Gateway.php
index 5ec22dd5..dd741ec5 100644
--- a/src/AKSRT/Payment/Gateway.php
+++ b/src/AKSRT/Payment/Gateway.php
@@ -227,16 +227,21 @@ class Gateway {
      * @return bool
      */
     public function complete_order(string $gateway_id, array $verify): bool {
-        $order_number = sanitize_text_field((string) ($verify['order_number'] ?? ''));
-        if ($order_number === '' || !class_exists('AKSRT\\Payment\\OrderRepository')) {
+        $provider_out_trade_no = sanitize_text_field((string) ($verify['order_number'] ?? ''));
+        if ($provider_out_trade_no === '' || !class_exists('AKSRT\\Payment\\OrderRepository')) {
             return false;
         }
 
         $repo  = OrderRepository::get_instance();
-        $order = $repo->get($order_number);
+        // Callbacks may carry attempt-suffixed out_trade_no (…P2); map back to local order.
+        $order = $repo->resolve_by_out_trade_no($provider_out_trade_no);
         if (!$order) {
             return false;
         }
+        $order_number = sanitize_text_field((string) ($order['order_number'] ?? ''));
+        if ($order_number === '') {
+            return false;
+        }
 
         $stored_gateway = sanitize_key((string) ($order['payment_method'] ?? ''));
         if ($stored_gateway === '' || !hash_equals($stored_gateway, sanitize_key($gateway_id))) {
@@ -253,8 +258,9 @@ class Gateway {
             || abs($expected - $paid_amount) > 0.01) {
             if (defined('WP_DEBUG') && WP_DEBUG) {
                 error_log(sprintf(
-                    '[AKSRT Payment] invalid completion order=%s expected=%.2f paid=%.2f transaction=%s gateway=%s',
+                    '[AKSRT Payment] invalid completion order=%s out_trade_no=%s expected=%.2f paid=%.2f transaction=%s gateway=%s',
                     $order_number,
+                    $provider_out_trade_no,
                     $expected,
                     $paid_amount,
                     $transaction_id !== '' ? 'present' : 'missing',
diff --git a/src/AKSRT/Payment/Gateways/AlipayGateway.php b/src/AKSRT/Payment/Gateways/AlipayGateway.php
index c920203d..1246e15d 100644
--- a/src/AKSRT/Payment/Gateways/AlipayGateway.php
+++ b/src/AKSRT/Payment/Gateways/AlipayGateway.php
@@ -40,11 +40,17 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 		}
 
 		$order_number = (string) ($order['order_number'] ?? '');
+		$out_trade_no = (string) ($order['out_trade_no'] ?? '');
+		if ($out_trade_no === '') {
+			$out_trade_no = class_exists('\AKSRT\Payment\OrderRepository')
+				? \AKSRT\Payment\OrderRepository::provider_out_trade_no($order)
+				: $order_number;
+		}
 		$amount       = (float) ($order['amount'] ?? 0);
 		$subject      = (string) ($order['subject'] ?? __('订单支付', 'aksrt'));
 		$payment_type = $this->get_config()['payment_type'];
 
-		if ($order_number === '' || $amount <= 0) {
+		if ($order_number === '' || $out_trade_no === '' || $amount <= 0) {
 			return ['success' => false, 'message' => __('订单参数无效', 'aksrt')];
 		}
 
@@ -53,7 +59,7 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 
 			$payload = [
 				'_method'      => 'GET',
-				'out_trade_no' => $order_number,
+				'out_trade_no' => $out_trade_no,
 				'total_amount' => number_format($amount, 2, '.', ''),
 				'subject'      => mb_substr($subject, 0, 256),
 			];
@@ -70,7 +76,10 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 			return [
 				'success'      => true,
 				'payment_url'  => $payment_url,
-				'payment_data' => ['order_number' => $order_number],
+				'payment_data' => [
+					'order_number' => $order_number,
+					'out_trade_no' => $out_trade_no,
+				],
 				'message'      => __('支付宝支付链接已生成', 'aksrt'),
 			];
 		} catch (\Throwable $e) {
@@ -140,10 +149,12 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 			return ['success' => false, 'message' => __('支付宝未配置', 'aksrt')];
 		}
 
+		$out_trade_no = $this->resolve_out_trade_no($order_number);
+
 		try {
 			YansongdaPayFactory::boot_alipay();
 			$result = Pay::alipay()->query([
-				'out_trade_no' => $order_number,
+				'out_trade_no' => $out_trade_no,
 			]);
 			$data = YansongdaPayFactory::to_array($result);
 
@@ -157,7 +168,8 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 
 			return [
 				'success'        => true,
-				'order_number'   => (string) ($data['out_trade_no'] ?? $order_number),
+				// Keep provider out_trade_no for Gateway::complete_order resolve.
+				'order_number'   => (string) ($data['out_trade_no'] ?? $out_trade_no),
 				'amount'         => (float) ($data['total_amount'] ?? 0),
 				'transaction_id' => (string) ($data['trade_no'] ?? ''),
 				'status'         => $status,
@@ -167,6 +179,25 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 		}
 	}
 
+	/**
+	 * Best-effort close of a previous provider trade before re-pay.
+	 */
+	public function close_trade(string $out_trade_no): void {
+		$out_trade_no = sanitize_text_field($out_trade_no);
+		if ($out_trade_no === '' || !$this->is_configured()) {
+			return;
+		}
+		try {
+			YansongdaPayFactory::boot_alipay();
+			// alipay.trade.close — supported by yansongda as close().
+			Pay::alipay()->close([
+				'out_trade_no' => $out_trade_no,
+			]);
+		} catch (\Throwable $e) {
+			// ignore
+		}
+	}
+
 	public function refund(string $order_number, float $amount, string $request_id = ''): array {
 		if ($amount <= 0) {
 			return ['success' => false, 'status' => 'failed', 'message' => __('退款金额无效', 'aksrt')];
@@ -175,6 +206,8 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 			return ['success' => false, 'message' => __('支付宝未配置', 'aksrt')];
 		}
 
+		$out_trade_no = $this->resolve_out_trade_no($order_number);
+
 		try {
 			YansongdaPayFactory::boot_alipay();
 			$refund_request_id = (string) preg_replace(
@@ -183,7 +216,7 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 				$request_id !== '' ? $request_id : $order_number . '_refund'
 			);
 			$result = Pay::alipay()->refund([
-				'out_trade_no'   => $order_number,
+				'out_trade_no'   => $out_trade_no,
 				'refund_amount'  => number_format($amount, 2, '.', ''),
 				'refund_reason'  => __('用户申请退款', 'aksrt'),
 				'out_request_no' => $refund_request_id,
@@ -216,7 +249,7 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 			YansongdaPayFactory::boot_alipay();
 			$params = ['out_request_no' => $request_id, '_action' => 'refund'];
 			if ($order_number !== '') {
-				$params['out_trade_no'] = $order_number;
+				$params['out_trade_no'] = $this->resolve_out_trade_no($order_number);
 			}
 			$result = Pay::alipay()->query($params);
 			$data = YansongdaPayFactory::to_array($result);
@@ -255,4 +288,17 @@ class AlipayGateway implements \AKSRT\Payment\GatewayInterface {
 			'payment_type'       => $type,
 		];
 	}
+
+	/**
+	 * Map local order_number → provider out_trade_no (supports resume attempts).
+	 */
+	private function resolve_out_trade_no(string $order_number): string {
+		if (class_exists('\AKSRT\Payment\OrderRepository')) {
+			$order = \AKSRT\Payment\OrderRepository::get_instance()->get($order_number);
+			if ($order) {
+				return \AKSRT\Payment\OrderRepository::provider_out_trade_no($order);
+			}
+		}
+		return $order_number;
+	}
 }
diff --git a/src/AKSRT/Payment/Gateways/EpayGateway.php b/src/AKSRT/Payment/Gateways/EpayGateway.php
index 716a7c9e..4e40cedf 100644
--- a/src/AKSRT/Payment/Gateways/EpayGateway.php
+++ b/src/AKSRT/Payment/Gateways/EpayGateway.php
@@ -44,9 +44,15 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 		}
 
 		$order_number = (string) ($order['order_number'] ?? '');
+		$out_trade_no = (string) ($order['out_trade_no'] ?? '');
+		if ($out_trade_no === '') {
+			$out_trade_no = class_exists('\AKSRT\Payment\OrderRepository')
+				? \AKSRT\Payment\OrderRepository::provider_out_trade_no($order)
+				: $order_number;
+		}
 		$amount       = (float) ($order['amount'] ?? 0);
 		$subject      = (string) ($order['subject'] ?? __('订单支付', 'aksrt'));
-		if ($order_number === '' || $amount <= 0) {
+		if ($order_number === '' || $out_trade_no === '' || $amount <= 0) {
 			return ['success' => false, 'message' => __('订单参数无效', 'aksrt')];
 		}
 
@@ -54,7 +60,7 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 		$params = [
 			'pid'          => $config['pid'],
 			'type'         => $this->channel,
-			'out_trade_no' => $order_number,
+			'out_trade_no' => $out_trade_no,
 			'notify_url'   => rest_url('aksrt/v1/payment/' . $this->get_id() . '/notify'),
 			'return_url'   => rest_url('aksrt/v1/payment/' . $this->get_id() . '/return'),
 			'name'         => mb_substr(wp_strip_all_tags($subject), 0, 127),
@@ -78,7 +84,7 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 			$body = json_decode((string) wp_remote_retrieve_body($response), true);
 			if (!is_array($body)) {
 				// Fall back to browser submit if mapi is unavailable.
-				return $this->browser_submit_result($config['apiurl'], $params, $order_number);
+				return $this->browser_submit_result($config['apiurl'], $params, $order_number, $out_trade_no);
 			}
 			$code = (int) ($body['code'] ?? 0);
 			if ($code !== 1) {
@@ -94,6 +100,7 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 				'success'      => true,
 				'payment_data' => [
 					'order_number' => $order_number,
+					'out_trade_no' => $out_trade_no,
 					'code_url'     => $qrcode,
 					'channel'      => $this->channel,
 				],
@@ -107,7 +114,7 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 			return $result;
 		}
 
-		return $this->browser_submit_result($config['apiurl'], $params, $order_number);
+		return $this->browser_submit_result($config['apiurl'], $params, $order_number, $out_trade_no);
 	}
 
 	public function verify_callback(\WP_REST_Request $request): array {
@@ -177,13 +184,14 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 			return ['success' => false, 'message' => __('易支付未配置', 'aksrt')];
 		}
 
+		$out_trade_no = $this->resolve_out_trade_no($order_number);
 		$config = $this->get_config();
 		// Common compatible query: api.php?act=order&pid&key&out_trade_no
 		$url = add_query_arg([
 			'act'          => 'order',
 			'pid'          => $config['pid'],
 			'key'          => $config['key'],
-			'out_trade_no' => $order_number,
+			'out_trade_no' => $out_trade_no,
 		], $this->endpoint($config['apiurl'], 'api.php'));
 
 		$response = wp_remote_get($url, ['timeout' => 20]);
@@ -205,7 +213,7 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 
 		return [
 			'success'        => true,
-			'order_number'   => (string) ($body['out_trade_no'] ?? $order_number),
+			'order_number'   => (string) ($body['out_trade_no'] ?? $out_trade_no),
 			'amount'         => $amount,
 			'transaction_id' => $tx,
 			'status'         => $paid ? 'paid' : 'pending',
@@ -297,16 +305,34 @@ class EpayGateway implements \AKSRT\Payment\GatewayInterface {
 	 * @param array<string,string> $params
 	 * @return array{success:bool,payment_url?:string,payment_data?:array,message?:string}
 	 */
-	private function browser_submit_result(string $apiurl, array $params, string $order_number): array {
+	/**
+	 * @param array<string,string> $params
+	 * @return array{success:bool,payment_url?:string,payment_data?:array,message?:string}
+	 */
+	private function browser_submit_result(string $apiurl, array $params, string $order_number, string $out_trade_no = ''): array {
 		$url = add_query_arg($params, $this->endpoint($apiurl, 'submit.php'));
 		return [
 			'success'      => true,
 			'payment_url'  => $url,
 			'payment_data' => [
 				'order_number' => $order_number,
+				'out_trade_no' => $out_trade_no !== '' ? $out_trade_no : $order_number,
 				'channel'      => $this->channel,
 			],
 			'message'      => __('易支付支付链接已生成', 'aksrt'),
 		];
 	}
+
+	/**
+	 * Map local order_number → provider out_trade_no (supports resume attempts).
+	 */
+	private function resolve_out_trade_no(string $order_number): string {
+		if (class_exists('\AKSRT\Payment\OrderRepository')) {
+			$order = \AKSRT\Payment\OrderRepository::get_instance()->get($order_number);
+			if ($order) {
+				return \AKSRT\Payment\OrderRepository::provider_out_trade_no($order);
+			}
+		}
+		return $order_number;
+	}
 }
diff --git a/src/AKSRT/Payment/Gateways/WechatPayGateway.php b/src/AKSRT/Payment/Gateways/WechatPayGateway.php
index 95b2af22..0a2ef90d 100644
--- a/src/AKSRT/Payment/Gateways/WechatPayGateway.php
+++ b/src/AKSRT/Payment/Gateways/WechatPayGateway.php
@@ -40,12 +40,19 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 		}
 
 		$order_number  = (string) ($order['order_number'] ?? '');
+		// Prefer attempt-specific out_trade_no so re-pay does not reuse a frozen provider order.
+		$out_trade_no  = (string) ($order['out_trade_no'] ?? '');
+		if ($out_trade_no === '') {
+			$out_trade_no = class_exists('\AKSRT\Payment\OrderRepository')
+				? \AKSRT\Payment\OrderRepository::provider_out_trade_no($order)
+				: $order_number;
+		}
 		$amount        = (float) ($order['amount'] ?? 0);
 		$subject       = (string) ($order['subject'] ?? __('订单支付', 'aksrt'));
 		$payment_type  = $this->get_config()['payment_type'];
 		$total_fen     = (int) round($amount * 100);
 
-		if ($order_number === '' || $total_fen <= 0) {
+		if ($order_number === '' || $out_trade_no === '' || $total_fen <= 0) {
 			return ['success' => false, 'message' => __('订单参数无效', 'aksrt')];
 		}
 
@@ -53,7 +60,7 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 			YansongdaPayFactory::boot_wechat();
 
 			$payload = [
-				'out_trade_no' => $order_number,
+				'out_trade_no' => $out_trade_no,
 				'description'  => mb_substr($subject, 0, 127),
 				'amount'       => [
 					'total'    => $total_fen,
@@ -76,7 +83,10 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 			}
 
 			$data = YansongdaPayFactory::to_array($result);
-			$payment_data = array_merge($data, ['order_number' => $order_number]);
+			$payment_data = array_merge($data, [
+				'order_number' => $order_number,
+				'out_trade_no' => $out_trade_no,
+			]);
 
 			$result_data = [
 				'success'      => true,
@@ -206,11 +216,13 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 			return ['success' => false, 'message' => __('微信支付未配置', 'aksrt')];
 		}
 
+		$out_trade_no = $this->resolve_out_trade_no($order_number);
+
 		try {
 			YansongdaPayFactory::boot_wechat();
 			$action = $this->query_action();
 			$result = Pay::wechat()->query([
-				'out_trade_no' => $order_number,
+				'out_trade_no' => $out_trade_no,
 				'_action'      => $action,
 			]);
 			$data = YansongdaPayFactory::to_array($result);
@@ -227,7 +239,8 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 
 			return [
 				'success'        => true,
-				'order_number'   => (string) ($data['out_trade_no'] ?? $order_number),
+				// Keep provider out_trade_no so Gateway::complete_order can resolve the local order.
+				'order_number'   => (string) ($data['out_trade_no'] ?? $out_trade_no),
 				'amount'         => ((int) YansongdaPayFactory::dig($data, 'amount.total', 0)) / 100,
 				'transaction_id' => (string) ($data['transaction_id'] ?? ''),
 				'status'         => $status,
@@ -237,17 +250,38 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 		}
 	}
 
+	/**
+	 * Best-effort close of a previous provider trade before re-pay.
+	 */
+	public function close_trade(string $out_trade_no): void {
+		$out_trade_no = sanitize_text_field($out_trade_no);
+		if ($out_trade_no === '' || !$this->is_configured()) {
+			return;
+		}
+		try {
+			YansongdaPayFactory::boot_wechat();
+			Pay::wechat()->close([
+				'out_trade_no' => $out_trade_no,
+				'_action'      => $this->query_action(),
+			]);
+		} catch (\Throwable $e) {
+			// ignore — new attempt still uses a fresh out_trade_no
+		}
+	}
+
 	public function refund(string $order_number, float $amount, string $request_id = ''): array {
 		if (!$this->is_configured()) {
 			return ['success' => false, 'message' => __('微信支付未配置', 'aksrt')];
 		}
 
+		$out_trade_no = $this->resolve_out_trade_no($order_number);
+
 		try {
 			YansongdaPayFactory::boot_wechat();
 			$action = $this->query_action();
 
 			$query = Pay::wechat()->query([
-				'out_trade_no' => $order_number,
+				'out_trade_no' => $out_trade_no,
 				'_action'      => $action,
 			]);
 			$q = YansongdaPayFactory::to_array($query);
@@ -267,7 +301,7 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 			);
 			$result = Pay::wechat()->refund([
 				'_action'       => 'refund_' . $action,
-				'out_trade_no'  => $order_number,
+				'out_trade_no'  => $out_trade_no,
 				'out_refund_no' => $refund_request_id,
 				'reason'        => __('用户申请退款', 'aksrt'),
 				'amount'        => [
@@ -350,4 +384,17 @@ class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {
 		$type = $this->get_config()['payment_type'];
 		return $map[$type] ?? 'native';
 	}
+
+	/**
+	 * Map local order_number → provider out_trade_no (supports resume attempts).
+	 */
+	private function resolve_out_trade_no(string $order_number): string {
+		if (class_exists('\AKSRT\Payment\OrderRepository')) {
+			$order = \AKSRT\Payment\OrderRepository::get_instance()->get($order_number);
+			if ($order) {
+				return \AKSRT\Payment\OrderRepository::provider_out_trade_no($order);
+			}
+		}
+		return $order_number;
+	}
 }
diff --git a/src/AKSRT/Payment/OrderRepositoryCore.php b/src/AKSRT/Payment/OrderRepositoryCore.php
index eb68cddc..c5493805 100644
--- a/src/AKSRT/Payment/OrderRepositoryCore.php
+++ b/src/AKSRT/Payment/OrderRepositoryCore.php
@@ -510,4 +510,135 @@ trait OrderRepositoryCore {
         return 'AKS' . date('YmdHis') . str_pad((string) random_int(0, 9999), 4, '0', STR_PAD_LEFT);
     }
 
+    /**
+     * Merge keys into the order note JSON payload (meta_payload).
+     *
+     * @param array<string,mixed> $patch
+     */
+    public function merge_meta(string $order_number, array $patch): bool {
+        global $wpdb;
+
+        $order = $this->get($order_number);
+        if (!$order) {
+            return false;
+        }
+
+        $meta = is_array($order['meta_payload'] ?? null) ? $order['meta_payload'] : [];
+        foreach ($patch as $key => $value) {
+            $meta[(string) $key] = $value;
+        }
+
+        $encoded = wp_json_encode($meta, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+        if (!is_string($encoded)) {
+            return false;
+        }
+
+        $updated = $wpdb->update(
+            $this->table(),
+            ['note' => $encoded],
+            ['order_number' => $order_number],
+            ['%s'],
+            ['%s']
+        );
+
+        return $updated !== false;
+    }
+
+    /**
+     * Resolve a local order from a provider out_trade_no (base or attempt-suffixed).
+     */
+    public function resolve_by_out_trade_no(string $out_trade_no): ?array {
+        $out_trade_no = sanitize_text_field($out_trade_no);
+        if ($out_trade_no === '') {
+            return null;
+        }
+
+        $direct = $this->get($out_trade_no);
+        if ($direct) {
+            return $direct;
+        }
+
+        // Resume attempts: {order_number}P{n}
+        if (preg_match('/^(AKS[0-9]{10,})P([0-9]{1,3})$/', $out_trade_no, $m)) {
+            $base = $this->get($m[1]);
+            if ($base) {
+                return $base;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Provider out_trade_no currently bound to this order (falls back to order_number).
+     *
+     * @param array<string,mixed> $order
+     */
+    public static function provider_out_trade_no(array $order): string {
+        $meta = is_array($order['meta_payload'] ?? null) ? $order['meta_payload'] : [];
+        $out  = sanitize_text_field((string) ($meta['provider_out_trade_no'] ?? ''));
+        if ($out !== '') {
+            return $out;
+        }
+        return sanitize_text_field((string) ($order['order_number'] ?? ''));
+    }
+
+    /**
+     * Allocate a new provider out_trade_no for a payment attempt.
+     * First attempt uses bare order_number; later attempts append Pn (WeChat limit 32).
+     *
+     * @return array{out_trade_no:string,attempt:int,previous:string}|null
+     */
+    public function allocate_payment_attempt(string $order_number): ?array {
+        $order = $this->get($order_number);
+        if (!$order) {
+            return null;
+        }
+
+        $meta     = is_array($order['meta_payload'] ?? null) ? $order['meta_payload'] : [];
+        $previous = sanitize_text_field((string) ($meta['provider_out_trade_no'] ?? ''));
+        $history  = is_array($meta['provider_out_trade_nos'] ?? null) ? $meta['provider_out_trade_nos'] : [];
+
+        // First provider submission keeps the bare order number.
+        // Re-pay (provider_out_trade_no already set) always mints a new suffix so
+        // WeChat/Alipay/Epay accept the order when amount/subject/notify changed.
+        if ($previous === '') {
+            $attempt = 1;
+            $out     = $order_number;
+        } else {
+            $attempt = max(1, (int) ($meta['pay_attempt'] ?? 1)) + 1;
+            $suffix  = 'P' . $attempt;
+            $base    = $order_number;
+            if (strlen($base) + strlen($suffix) > 32) {
+                $base = substr($base, 0, 32 - strlen($suffix));
+            }
+            $out = $base . $suffix;
+            if ($previous !== '' && !in_array($previous, $history, true)) {
+                $history[] = $previous;
+            }
+        }
+
+        if (!in_array($out, $history, true)) {
+            $history[] = $out;
+        }
+        if (count($history) > 20) {
+            $history = array_slice($history, -20);
+        }
+
+        $ok = $this->merge_meta($order_number, [
+            'pay_attempt'            => $attempt,
+            'provider_out_trade_no'  => $out,
+            'provider_out_trade_nos' => array_values($history),
+        ]);
+        if (!$ok) {
+            return null;
+        }
+
+        return [
+            'out_trade_no' => $out,
+            'attempt'      => $attempt,
+            'previous'     => $previous,
+        ];
+    }
+
 }
diff --git a/src/AKSRT/Payment/UserOrders.php b/src/AKSRT/Payment/UserOrders.php
index ab4ac488..83f4911b 100644
--- a/src/AKSRT/Payment/UserOrders.php
+++ b/src/AKSRT/Payment/UserOrders.php
@@ -337,6 +337,26 @@ class UserOrders {
 
         try {
             $order['subject'] = $order['subject'] ?? sprintf(__('订单 %s', 'aksrt'), $order_number);
+
+            $needs_attempt = !in_array($payment_method, ['balance', 'points'], true);
+            if ($needs_attempt) {
+                $attempt = $repo->allocate_payment_attempt($order_number);
+                if ($attempt === null) {
+                    return ['success' => false, 'message' => __('无法生成支付单号，请稍后重试。', 'aksrt')];
+                }
+                $order = $repo->get_user_order($user_id, $order_number) ?: $order;
+                $order['out_trade_no'] = (string) $attempt['out_trade_no'];
+                if (!empty($attempt['previous'])
+                    && $attempt['previous'] !== $attempt['out_trade_no']
+                    && method_exists($gateway, 'close_trade')) {
+                    try {
+                        $gateway->close_trade((string) $attempt['previous']);
+                    } catch (\Throwable $e) {
+                        // best-effort
+                    }
+                }
+            }
+
             $payment_result = $gateway->create_payment($order);
             if (empty($payment_result['success'])) {
                 return ['success' => false, 'message' => $payment_result['message'] ?? __('支付失败。', 'aksrt')];
diff --git a/src/AKSRT/Shop/CheckoutService.php b/src/AKSRT/Shop/CheckoutService.php
index 6677d7e9..13837b9f 100644
--- a/src/AKSRT/Shop/CheckoutService.php
+++ b/src/AKSRT/Shop/CheckoutService.php
@@ -226,6 +226,28 @@ class CheckoutService {
             return $this->pay_with_points($user_id, $order_number, $order);
         }
 
+        // External gateways: allocate a fresh out_trade_no so re-pay works when
+        // the provider rejects "same order number with changed params".
+        $needs_attempt = !in_array($payment_method, ['balance', 'points'], true);
+        if ($needs_attempt && class_exists('\AKSRT\Payment\OrderRepository')) {
+            $attempt = $repo->allocate_payment_attempt($order_number);
+            if ($attempt === null) {
+                return ['success' => false, 'message' => __('无法生成支付单号，请稍后重试。', 'aksrt')];
+            }
+            $order = $repo->get_user_order($user_id, $order_number) ?: $order;
+            $order['out_trade_no'] = (string) $attempt['out_trade_no'];
+            // Close previous provider trade when possible (WeChat/Alipay) so the new attempt is clean.
+            if (!empty($attempt['previous'])
+                && $attempt['previous'] !== $attempt['out_trade_no']
+                && method_exists($gateway, 'close_trade')) {
+                try {
+                    $gateway->close_trade((string) $attempt['previous']);
+                } catch (\Throwable $e) {
+                    // best-effort
+                }
+            }
+        }
+
         $payment_result = $gateway->create_payment($order);
         if (empty($payment_result['success'])) {
             return ['success' => false, 'message' => $payment_result['message'] ?? __('支付失败。', 'aksrt')];