# Update Payment Request Describes a request to update a payment using [UpdatePayment](../../doc/api/payments.md#update-payment). ## Structure `UpdatePaymentRequest` ## Fields | Name | Type | Tags | Description | | --- | --- | --- | --- | | `payment` | [`Payment \| undefined`](../../doc/models/payment.md) | Optional | Represents a payment processed by the Square API. | | `idempotencyKey` | `string` | Required | A unique string that identifies this `UpdatePayment` request. Keys can be any valid string
but must be unique for every `UpdatePayment` request.

For more information, see [Idempotency](https://developer.squareup.com/docs/build-basics/common-api-patterns/idempotency).
**Constraints**: *Minimum Length*: `1`, *Maximum Length*: `45` | ## Example (as JSON) ```json { "idempotency_key": "956f8b13-e4ec-45d6-85e8-d1d95ef0c5de", "payment": { "amount_money": { "amount": 1000, "currency": "USD" }, "tip_money": { "amount": 100, "currency": "USD" }, "version_token": "ODhwVQ35xwlzRuoZEwKXucfu7583sPTzK48c5zoGd0g6o", "id": "id6", "created_at": "created_at4", "updated_at": "updated_at2" } } ```