Validate a transaction

Use the validation endpoint to check whether a transaction request is valid before creating it.

Validation runs the same checks that occur during transaction creation but does not create or process a transaction. This allows you to confirm that your request meets all validation rules before submitting the payment.

POST /api/transactionRequests/validate

For the complete request and response schemas, see Validate transaction.

When to validate a transaction

You may want to validate a transaction request when you need to:

• Verify that all required fields are present
• Confirm that the request satisfies country and payment rules
• Check that the selected route is valid
• Preview the calculated FX route and value date

Validation is optional but useful when building or testing an integration.

Example request

{
  "SendCurrency": "EUR",
  "ReceiveValue": 100.00,
  "Recipient": {
    "Name": "Victoria Lau",
    "RecipientReference": "Claim-51837",
    "Country": "GB",
    "Currency": "GBP",
    "Account": {
      "SortCode": "112233",
      "AccountNumber": "22233445"
    }
  }
}

Example response

If the request passes validation, the API returns the calculated transaction details.

The response includes the calculated payment route, including:

• Source currency and value
• Destination currency and value
• Exchange rate
• Value date

{
  "Merchant": "Transfercorp UK Ltd",
  "Recipient": {
    "Country": "GB",
    "Currency": "GBP",
    "Name": "Victoria Lau",
    "RecipientReference": "Claim-51837"
  },
  "Route": {
    "DestinationCurrency": {
      "Currency": "GBP",
      "Value": 100.0
    },
    "ExchangeRate": 0.8518381869,
    "SourceCurrency": {
      "Currency": "EUR",
      "Value": 117.39
    }
  },
  "Status": "Pending",
  "TransactionId": "6d0b145b-ca8f-4611-a21c-9bf3380ad5c9"
}

Validation errors

If the request fails validation, the API returns a 400 Bad Request response.

The response includes a ModelState object. Each entry in ModelState identifies the field that failed validation and provides an error message describing the issue.

Example

{
  "Code": "ArgumentInvalid",
  "Message": "One or more arguments passed to the API call have an invalid value.",
  "ModelState": {
    "request.Recipient.RecipientReference": {
      "Errors": [
        {
          "ErrorMessage": "This field is required."
        }
      ]
    }
  }
}

Next step

After the request passes validation, send the transaction.

See Send an immediate transaction.