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

# promo_code_requires_paid_plan

> Promo codes can only be applied to paid plans

|                 |                                 |
| --------------- | ------------------------------- |
| **HTTP status** | `400 Bad Request`               |
| **Error code**  | `promo_code_requires_paid_plan` |

## What happened

A promo code was submitted with a plan change whose target plan is unpaid (for example a pay-as-you-go plan). An unpaid plan has no recurring fee for a discount to apply to, so the code is rejected and the plan change is not performed.

## How to fix

<Steps>
  <Step title="Retry without the code or with a paid target">
    The same request succeeds without the `promo_code` field; only the discount is affected. To use the code, target a paid plan instead.
  </Step>
</Steps>