> For the complete documentation index, see [llms.txt](https://developer.paddle.com/llms.txt).

# Price has duplicate allowances for a usage balance unit

A price can have only one allowance for each usage balance unit, but `allowances` includes the same `usage_balance_unit_id` more than once.

> **Early access (beta): usage-based billing**

---

## Example

```json
{
  "error": {
    "type": "request_error",
    "code": "price_allowance_duplicate_usage_balance_unit",
    "detail": "usage balance unit ubu_01kw8ta2j8x5t7q4v9m1kd6phz appears more than once in allowances",
    "documentation_url": "https://developer.paddle.com/errors/prices/price_allowance_duplicate_usage_balance_unit"
  },
  "meta": {
    "request_id": "00000000-0000-0000-0000-000000000000"
  }
}
```

## Details

| Attribute | Value |
| --- | --- |
| Status code | 400 |
| Error code | `price_allowance_duplicate_usage_balance_unit` |
| Error message | usage balance unit %s appears more than once in allowances |

## Common causes

- Two or more entries in `allowances` have the same `usage_balance_unit_id`.
- When updating a price, `allowances` replaces the existing allowances in full. The request adds a new entry for a usage balance unit that's already in the list, instead of changing the `amount` on the existing entry.

## Common solutions

- Combine the duplicate entries into one allowance, with `amount` set to the total amount of the usage balance unit that the price should grant each billing period.
- If one of the entries is meant for a different usage balance unit, correct its `usage_balance_unit_id`.