# Merchant seller identifier

Source: https://developer.avalara.com/marketplace-integration-guide/designing/merchant-seller-identifier-sales/

**Endpoints used:** [LineItemModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/LineItemModel/)

To track merchant transactions on your marketplace, you can use the `merchantSellerIdentifier` field. This field identifies the merchant facilitating sales on your marketplace.

[![Closed](https://avalara-devdocs-prod.mcoutput.com/avatax-for-marketplaces/Content/Skins/Default/Stylesheets/Images/transparent.gif)Example](javascript:void\(0\);)

```
"lines": [  {    "number": "1",    "quantity": 1,    "amount": 100,    "taxCode": "PS081282",    "itemCode": "Y0001",    "description": "Yarn",    "discounted": false,    "merchantSellerIdentifier": "Merchant12345"  }] 
```