# Support tax-only adjustments

Source: https://developer.avalara.com/marketplace-integration-guide/transactions/certification-requirements/support-tax-only-adjustments/

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

If your platform supports tax-only refunds, then include this support in your integration. For example, you may encounter a scenario where you charged a customer tax, but the customer later realizes that they have an exemption certificate. After the original transaction is posted, the customer can provide you with their exemption certificate. In this case, you issue that customer a tax-only refund if this is supported in your platform.

Issuing tax-only refunds can be accomplished with the [RefundTransaction](https://developer.avalara.com/api-reference/avatax/rest/v2/methods/Transactions/RefundTransaction/) API by specifying a `RefundType` of `TaxOnly`. Your application should recognize the tax amount that was calculated on the original transaction using the `transactionCode` specified in the endpoint URL and then pass that as the value for the refunded tax value. In the example below, the code for the original transaction is `TestTransactions3`.

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

```
 curl    -X POST    -H 'Accept: application/json'    -H 'Authorization: Basic ${btoa!(`:`)}'    -H 'Content-Type: application/json'    --data '{        "refundTransactionCode": "TestRefunds3",        "refundDate": "2024-07-12",        "refundType": "TaxOnly",        "referenceCode": "Refund tax for a committed transaction"    }'    'https://sandbox-rest.avatax.com/api/v2/companies/DEFAULT/transactions/TestTransactions3/refund' 
```