# Fees and rates in responses

Source: https://developer.avalara.com/erp-integration-guide/transactions/fees-and-rates-in-responses/

In transaction responses, the [TransactionLineDetailModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/TransactionLineDetailModel/) describes how AvaTax calculated tax for a line item. When reviewing this detail, take note of both the `rate` and `isFee` fields. These fields describe whether a rate or amount was used for the tax calculation.

-   When `"isFee": false`, this represents a tax rate percentage. In this case, `"rate": 0.022500` indicates a 2.25% tax rate.

-   When `"isFee": true`, this represents a specific monetary amount. For example, if `"currencyCode": "USD"` and `"isFee": true`, then `"rate": 15` indicates a fee of $15.00 USD.

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

```
"details": [  {    "id": 85059721380033,    ...,    "rate": 0.2,    ...,    "isFee": false,    ...,  },  ...]
```