diff --git a/source/schemas/shopping/types/line_item.json b/source/schemas/shopping/types/line_item.json
index 0eba9ed0..ba2370a8 100644
--- a/source/schemas/shopping/types/line_item.json
+++ b/source/schemas/shopping/types/line_item.json
@@ -41,6 +41,15 @@
         "create": "omit",
         "update": "optional"
       }
+    },
+    "buyer_notes": {
+      "type": "string",
+      "maxLength": 500,
+      "description": "Free-text buyer instructions for this line item (e.g., customization requests, gift messages, dietary notes). Business MAY act on, echo back, or ignore.",
+      "ucp_request": {
+        "create": "optional",
+        "update": "optional"
+      }
     }
   }
 }
diff --git a/source/schemas/shopping/types/order_line_item.json b/source/schemas/shopping/types/order_line_item.json
index 5f639dcf..c79e4a08 100644
--- a/source/schemas/shopping/types/order_line_item.json
+++ b/source/schemas/shopping/types/order_line_item.json
@@ -61,6 +61,11 @@
     "parent_id": {
       "type": "string",
       "description": "Parent line item identifier for any nested structures."
+    },
+    "buyer_notes": {
+      "type": "string",
+      "maxLength": 500,
+      "description": "Buyer instructions for this line item, preserved from checkout. Business SHOULD surface these in fulfillment workflows."
     }
   }
 }