# Tax code

Source: https://developer.avalara.com/avatax-dm-combined-erp/sales-tax-badge/transactions/cert-tax-code/

# Tax code

**Element type: Required**

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

Your UI must include a method for allowing users to specify a tax code for each line item in a transaction. You can use your own tax code mapping or standard Avalara tax codes. For a full list of tax codes, run the [ListTaxCodes API](https://developer.avalara.com/api-reference/avatax/rest/v2/methods/Definitions/ListTaxCodes/), or you can use the [Avalara Tax Code Search](https://taxcode.avatax.avalara.com/) tool.

Tax codes are specified using the`taxCode` field on the [LineItemModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/LineItemModel/). This field is optional for users. If a tax code is not specified, then AvaTax will treat that item as a taxable item. More information about Avalara tax codes is available in the [Avalara tax codes](https://knowledge.avalara.com/bundle/dqa1657870670369_dqa1657870670369/page/Avalara_tax_codes.html) article in the Knowledge Center.

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

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