# Void/unvoid transactions

Source: https://developer.avalara.com/products/communications/integration-guides/communications-integration/iut2454468846741/

Guide: Communications

# Void/unvoid transactions

**Element type: Conditional**

**Enpoints/models used:** [Commit](https://developer.avalara.com/api-reference/communications/v2/methods/Tax%20Calculation/Commit/)

If the source application supports void/delete functions, then your integration must update the corresponding transaction with the current transaction status. This is done using the `cmmt` flag in the [Commit](https://developer.avalara.com/api-reference/communications/v2/methods/Tax%20Calculation/Commit/) endpoint.

Note

Don’t use the `cmmt` flag in a `CalculateTaxes` request to uncommit a committed document. The `cmmt` flag in a `CalculateTaxes` request is a "use-once" feature that establishes the state of ALL the transactions for a particular document on its first call in a particular reporting month. Even if you try to set the `cmmt` flag to something else in the `CalculateTaxes` request, the commit state won’t change. Refer to the [When to commit](https://developer.avalara.com/communications-integration/design-transaction-workflow/when-to-commit) topic for more information and examples.

**View example**:

```
 {
  "doc": "DocumentCode12345",
  "cmmt": true,
} 
```