---
title: "409 Insufficient credits"
description: "The customer did not have enough credits for this charge. QuotaStack charged nothing."
---

# 409 Insufficient credits

`https://api.quotastack.io/errors/insufficient-credits`

The customer did not have enough credits for this charge. QuotaStack charged nothing.

## Why it happened

- The balance is below what the call costs.
- An open [reservation](/docs/concepts/reservations) is holding credits, so `effective_balance` is lower than `balance`.
- A block that would pay for this starts later, through `stack_after`.
- Your [overage](/docs/concepts/credits) policy is `block`, which is what a new account starts with.

## How to fix it

1. Read `effective_balance`, not `balance`. That is what a new charge can spend.
2. Grant or sell more credits, then send the call again.
3. Listen for `credit.low_balance`, so you can tell the customer before this happens.
4. Set your [overage](/docs/concepts/credits) policy to `allow` or `notify`, and QuotaStack will note the gap instead.

### Example response 409

```json
{
  "type": "https://api.quotastack.io/errors/insufficient-credits",
  "title": "Insufficient Credits",
  "status": 409,
  "detail": "Customer has insufficient credits for this operation."
}
```

## Which calls return this

- [`POST /v1/customers/{customer_id}/credits/adjust`](/docs/api/credits#adjustCustomerCredits)
- [`POST /v1/customer-by-external-id/{external_id}/credits/adjust`](/docs/api/credits#adjustCustomerCreditsByExternalId)
- [`POST /v1/reservations/{id}/commit`](/docs/api/reservations#commitReservation)

## See also

- [Credits](/docs/concepts/credits)
- [Low balance alerts](/docs/cookbook/low-balance-alerts)