# order-id

###### Order identifier of the merchant system; must be passed to Ratepay

↔ Request/Response parameter

## `<order-id>`

**The `<order-id>` must be passed to Ratepay** with the Payment Request or Payment Confirm (or, at the very latest, with the Confirmation Deliver) to facilitate identification of the customers’ payments in Ratepay's backend.

| Type | Condition | Restriction |
|  --- | --- | --- |
| xs:string | Mandatory with either:- `PAYMENT_REQUEST`- `PAYMENT_CONFIRM`- `CONFIRMATION_DELIVER` | Length <=50 |