# Middleman VAT ID

Source: https://developer.avalara.com/avatax-for-vat/wdb4413978240150/

# Middleman VAT ID

Learn about the Middleman VAT ID parameter required for triangulation scenarios.

**Element type:** Required for Triangulation

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

Your integration must allow users to specify the VAT ID of the middleman in triangulation scenarios. This is done using the `MiddlemanVatId` parameter in the [TransactionParameterModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/TransactionParameterModel/) or [TransactionLineParam](https://developer.avalara.com/api-reference/avatax/rest/v2/models/TransactionLineParameterModel/)[eterModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/TransactionLineParameterModel/). When providing the `MiddlemanVatId`, you must include the complete VAT ID, starting with the two-digit country ISO prefix.

**Example**

```
{
  "parameters":[
    {
      "name": "Transport",
      "value": "Seller"
    },
    {
      "name": "IsTriangulation",
      "value": "true"
    },
    {
      "name": "MiddlemanVatId",
      "value": "DK12345678"
    }
  ]
  ...
}
```