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# HasReferenceSchemeTransactionId

Matches transactions that carry (or do not carry) a scheme transaction ID — used to recognise follow-up transactions that need a credentials-on-file identifier. Shown as "Has Reference Scheme Transaction ID" in the condition catalogue.

## Parameters

| Field                 | Type   | Required | Allowed values    |
| --------------------- | ------ | -------- | ----------------- |
| `schemeRefIdExpected` | string | yes      | `"yes"` or `"no"` |

## Example

```json
{
  "constraint": "HasReferenceSchemeTransactionId",
  "params": { "schemeRefIdExpected": "yes" }
}
```

## Notes

* **Availability:** might not be included in your platform package — if this condition is missing from the catalogue returned by [List routing constraints](https://documentation.ixopay.com/api/provisioning/list-routing-constraints), contact your Customer Success Manager to have it activated.