diff --git a/packages/graphql/api/orders.ts b/packages/graphql/api/orders.ts
index f64eded..f9b55fa 100644
--- a/packages/graphql/api/orders.ts
+++ b/packages/graphql/api/orders.ts
@@ -67,6 +67,15 @@ export class OrdersService extends BaseService {
       }
     }
 
+    if (isMaster) {
+      const { customers: myMasters } = await customersService.getMasters(this.customer);
+
+      const clientId = variables.input.client;
+      const isTryingToRecordMaster = myMasters.some((master) => master?.documentId === clientId);
+
+      if (isTryingToRecordMaster) throw new Error(ERRORS.INVALID_CLIENT);
+    }
+
     if (isMaster && slot?.master?.documentId !== customer.documentId) {
       throw new Error(ERRORS.INVALID_MASTER);
     }