# AvaTax tax code mapping

Source: https://developer.avalara.com/marketplace-integration-guide/designing/tax-code-mapping/

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

Marketplace integrations should provide a way for tax codes to be mapped to AvaTax prior to a sale. We recommend that you work with Avalara to take all of the categories that a seller can list an item under, and then map those categories to tax codes. When done, the seller chooses the item and category it's under, and the corresponding tax code is sent to AvaTax.

In your integration, some users will choose to enter a tax code directly into the UI. Others will want to search for or be provided with a list of tax codes. A common use case is to show a dropdown text box with all available tax codes. In this example, when a customer starts typing the word `C`, your program can call [ListTaxCodes](https://developer.avalara.com/api-reference/avatax/rest/v2/methods/Definitions/ListTaxCodes/) to find all tax codes that begin with `C`. Below is an example showing how to call [ListTaxCodes](https://developer.avalara.com/api-reference/avatax/rest/v2/methods/Definitions/ListTaxCodes/) and filter on tax codes that start with `C`.

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

```
GET /api/v2/definitions/taxcodes/$filter=description startswith C
```

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

```
{  "id": 56789,  "companyId": 12345,  "taxCode": "PF050101",  "taxCodeTypeId": "P",  "description": "Carbonated beverages",  "parentTaxCode": "PF050001",  "isPhysical": true,  "goodsServiceCode": 0,  "entityUseCode": "",  "isActive": true,  "isSSTCertified": true} 
```