> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nozle.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Legacy Invoice Wallet Balance

Get the legacy invoice wallet balance for a customer.

**Auth:** secret key only. Publishable keys are always rejected.

<Warning>
  This is not a product Credit System balance. New integrations should use [Customer Credit Balances](/api/customer-credit-balances).
</Warning>

<ParamField path="id" type="string" required>
  External customer ID
</ParamField>