diff --git a/src/orders/dto/order.dto.ts b/src/orders/dto/order.dto.ts
index 1a39775..7936626 100644
--- a/src/orders/dto/order.dto.ts
+++ b/src/orders/dto/order.dto.ts
@@ -2,6 +2,7 @@ import {
   ArrayMinSize,
   IsDateString,
   IsEnum,
+  IsIn,
   IsInt,
   IsNumber,
   IsOptional,
@@ -166,4 +167,9 @@ export class ListOrdersDto {
   @Min(0)
   @Type(() => Number)
   maxTotal?: number;
+
+  /** Filter by payment outcome derived from transactions. */
+  @IsOptional()
+  @IsIn(['paid', 'unpaid', 'failed'])
+  paymentStatus?: 'paid' | 'unpaid' | 'failed';
 }
diff --git a/src/orders/orders.service.ts b/src/orders/orders.service.ts
index b57ddd6..7e486c5 100644
--- a/src/orders/orders.service.ts
+++ b/src/orders/orders.service.ts
@@ -155,6 +155,7 @@ export class OrdersService {
             customer: this.buildCustomerSearchFilter(query.customerQuery.trim()),
           }
         : {}),
+      ...this.paymentStatusWhere(query.paymentStatus),
     };
 
     const [items, total] = await Promise.all([
@@ -762,6 +763,43 @@ export class OrdersService {
     return { OR: or };
   }
 
+  private paymentStatusWhere(
+    paymentStatus: 'paid' | 'unpaid' | 'failed' | undefined,
+  ): Prisma.OrderWhereInput {
+    if (paymentStatus === 'paid') {
+      return {
+        transactions: { some: { status: 'completed' } },
+      };
+    }
+    if (paymentStatus === 'failed') {
+      return {
+        AND: [
+          { transactions: { some: { status: 'failed' } } },
+          { transactions: { none: { status: 'completed' } } },
+        ],
+      };
+    }
+    if (paymentStatus === 'unpaid') {
+      return {
+        transactions: { none: { status: 'completed' } },
+      };
+    }
+    return {};
+  }
+
+  private derivePaymentStatus(
+    transactions: Array<{ status: string }>,
+  ): 'paid' | 'unpaid' | 'failed' {
+    if (transactions.some((tx) => tx.status === 'completed')) return 'paid';
+    if (
+      transactions.length > 0 &&
+      transactions.every((tx) => tx.status === 'failed')
+    ) {
+      return 'failed';
+    }
+    return 'unpaid';
+  }
+
   private async defaultProcessStepId(businessId: bigint) {
     const steps = await this.businessSettings.getOrderProcessSteps(businessId);
     return steps[0]?.id ?? 'processing';
@@ -873,6 +911,7 @@ export class OrdersService {
       processStepLabel: processStep?.label ?? null,
       processStepLabelFa: processStep?.labelFa?.trim() || null,
       processStepColor: processStep?.color ?? null,
+      paymentStatus: this.derivePaymentStatus(order.transactions ?? []),
       source: order.source,
       subtotal: Number(order.subtotal),
       shippingTotal: Number(order.shippingTotal),