# POST /api/v1/onboarding/prepare-checkout

> Create Stripe Checkout session for onboarding

- **Tag:** onboarding
- **Operation ID:** `prepare_checkout_api_v1_onboarding_prepare_checkout_post`

## Description

Collects plan and add-on selections, creates a Stripe Checkout session with a 30-day trial. Business is NOT created until /complete is called.

## Authentication

Bearer token in `Authorization` header.
Required header: `x-business-id: <business uuid>`.

## Request body

Schema: `PrepareCheckoutRequest`

- `account_type` (string · required) — 'self-managed', 'dz-managed', or 'advisory-firm'
- `business_name` (string · required)
- `mailbox` (string · required)
- `default_currency` (string) — Default business currency. Supported out of the box: USD, CAD, AUD, EUR, GBP.
- `tax_year_end_month` (integer)
- `selected_addons` (array · string) — Optional list of addon slugs to include on the Stripe Checkout. Capped at 50 entries.
- `trial_agreed` (boolean · required) — User has agreed to the 30-day free trial terms
- `firm_name` (string)
- `firm_plan_tier` (string) — Graduated firm plan tier (defaults to firm_starter)
- `ein` (string)
- `logo_url` (string)
- `address` (string)
- `num_full_time_accountants` (integer)
- `num_part_time_accountants` (integer)
- `current_tools` (array · string)
- `success_path` (string) — Optional path-only override (no host) to land on after Stripe Checkout. Defaults to /onboarding/complete.
- `cancel_path` (string) — Optional path-only override (no host) for cancelled checkout. Defaults to /welcome.

## Responses

### 201 — Successful Response

Schema: `PrepareCheckoutResponse`

- `checkout_url` (string · required)
- `session_id` (string · required)

### 400 — Bad Request - Invalid input

### 409 — Conflict - Resource already exists

### 422 — Validation Error

Schema: `HTTPValidationError`

- `detail` (array · ValidationError) → `ValidationError`
  - `loc` (array · string | integer · required)
  - `msg` (string · required)
  - `type` (string · required)
  - `input` (object)
  - `ctx` (object)

### 429 — Too Many Requests - Rate limit exceeded

## Code samples

### cURL

```bash
curl -X POST 'https://api.ondayzero.com/api/v1/onboarding/prepare-checkout' \
  -H 'Authorization: Bearer dz_your_token' \
  -H 'x-business-id: YOUR_BUSINESS_ID' \
  -H 'Content-Type: application/json' \
  -d '{
  "account_type": "string",
  "business_name": "string",
  "mailbox": "string",
  "trial_agreed": false
}'
```

### JavaScript

```javascript
const response = await fetch('https://api.ondayzero.com/api/v1/onboarding/prepare-checkout', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer dz_your_token',
    'x-business-id': 'YOUR_BUSINESS_ID',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
  "account_type": "string",
  "business_name": "string",
  "mailbox": "string",
  "trial_agreed": false
}),
});
const data = await response.json();
```

### Python

```python
import httpx

headers = {
    "Authorization": "Bearer dz_your_token",
    "x-business-id": "YOUR_BUSINESS_ID",
}

payload = {
  "account_type": "string",
  "business_name": "string",
  "mailbox": "string",
  "trial_agreed": false
}

response = httpx.post("https://api.ondayzero.com/api/v1/onboarding/prepare-checkout", headers=headers, json=payload)
data = response.json()
```

## See also

- HTML version: https://www.ondayzero.com/docs/reference/onboarding/prepare-checkout
- OpenAPI slice: https://www.ondayzero.com/docs/reference/onboarding/prepare-checkout/openapi.json
- Other endpoints in **onboarding**: https://www.ondayzero.com/docs/reference/onboarding