---
title: "Start a plan change checkout"
method: POST
path: "/billing/plan/checkout"
tags: ["Billing"]
---

# Start a plan change checkout

`POST /billing/plan/checkout`

## Request

- Base URL: `https://api.cactal.ai/v1`
- URL: `https://api.cactal.ai/v1/billing/plan/checkout`
- Auth: HTTP bearer

Applies a plan change or starts hosted checkout. Monthly-to-annual switches apply immediately; annual-to-monthly at renewal. Redirect the customer to `paymentUrl` when non-null; null means the change applied without a payment step. Rejected while billing is past due; requires the organization owner.

## Request body

- object
  - `plan` 'pro', required
  - `interval` 'monthly' | 'annual', required
  - `organizationId` string, required
  - `aiCreditTier` 1000 | 2000 | 4000 | 8000 | 12000 | 20000 | 30000 | 40000 | 50000 | 75000 | 100000
  - `successUrl` string
  - `idempotencyKey` string

## Response `200`

Checkout result for the plan change.

- object
  - `paymentUrl` string, nullable, required: Hosted checkout URL to redirect the customer to. `null` when the change was applied directly without a payment step.

## Other responses

- `400`: Validation failed. The response `message` names the first invalid field.
- `401`: Missing, invalid, expired, or revoked API key.
- `403`: The authenticated principal lacks the required capability.
- `404`: The resource does not exist or is outside the principal’s access scope.
- `429`: Rate limit exceeded. Retry after the number of seconds in the `Retry-After` header.

---

[API](https://skmtc.dev/cactal/apis/cactal-api.md) · [All operations](https://skmtc.dev/cactal/apis/cactal-api/llms.txt) · [OpenAPI document](https://skmtc.dev/cactal/apis/cactal-api/revisions/9cd0fb5eacdd?raw)