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

# Checkout on Behalf Of (OBO)

**Release Type:** Enhancement

## Summary

Platform merchants can now create Checkout sessions and collect payments **on behalf of their sub-entities** — such as sellers, agents, wallet providers, or utility companies. This extends Tazapay's existing On Behalf Of (OBO) pattern, already available for Payouts (POBO) and Collections (COBO), into the Checkout and Payin flows.

When a merchant creates a checkout with `on_behalf_of`, Tazapay validates that the entity belongs to the merchant and, depending on merchant configuration, may require the entity to be explicitly approved before the checkout can proceed.

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## What Changed

### New fields on Checkout API

The following optional fields have been added to the Checkout object (`POST /v3/checkout`, `GET /v3/checkout/{id}`):

* **`on_behalf_of`** (string, optional)

  ID of the entity on whose behalf the checkout session is created. The entity must belong to the merchant account. Format: `ent_*`.

### New fields on Payin API

When a checkout is created with `on_behalf_of`, the resulting Payin **automatically inherits** the OBO fields:

* **`on_behalf_of`** (string) — Inherited from the associated checkout session.

### Webhook Updates

All checkout and payin webhook events now include `on_behalf_of` in the event `data` payload when the checkout/payin was created in an OBO context. This applies to:

* `checkout.created`, `checkout.paid`, `checkout.expired`, `checkout.tax_invoice_generated`
* `payment_attempt.created`, `payment_attempt.failed`, `payment_attempt.processing`, `payment_attempt.succeeded`
* `payin.requires_payment_method`, `payin.requires_action`, `payin.processing`, `payin.succeeded`, `payin.cancelled`, `payin.created`

## Affected Endpoints

* `POST /v3/checkout` — request and response updated
* `GET /v3/checkout/{id}` — response updated

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## Compatibility

No breaking changes. All new fields are optional. Existing integrations that do not send `on_behalf_of` will continue to work without modification.

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## Relevant Links

1. [Checkout on Behalf Of Integration Guide](/cards/checkout-on-behalf-of/checkout-on-behalf-of)
2. [Checkout API Reference](/api-reference/tazapay-api/checkout)
3. [Payin API Reference](/api-reference/tazapay-api/payin)
4. [Checkout Webhook Events](/api-reference/tazapay-api/checkout-webhooks)
5. [Payin Webhook Events](/api-reference/tazapay-api/payin-webhook)