Single immediate payments

A single immediate payment is a one time payment, executed immediately, that requires the user to authenticate with their bank.

Below are instructions for how to:

1. Build a provider selection screen for your users to select their bank
2. Create a payment
3. Redirect a user to authenticate
4. Handle the user returning to your application
5. Poll for payment status

Build a provider selection screen

The providers endpoint serves two purposes:

1. Tells you which banks are active, if a bank isn't listed then we have deactivated it temporarily until its service is returned.
2. Gives you the assets to build out a selection screen, for example, logos and icons.

When querying the endpoint, specify capability in the query string as SingleImmediatePayment.

Each bank available will have the following fields:

We recommend you query this endpoint every single time you make a payment as we will remove banks that are not currently available.

• The steps parameter structure

https://pay-api.truelayer.com/providers?capability=SingleImmediatePayment

{
  "results":[
    {
      "id":"ob-sandbox-natwest",
      "logo":"example.com",
      "icon":"example.com",
      "displayable_name":"Natwest Sandbox",
      "main_bg_color":"#eee",
      "supports_app_to_app":false,
      "divisions":["retail"]
    }
  ]
}

Create a payment

This method includes the following fields:

curl -X POST \
     -H "Authorization: Bearer ${access_token}" \
     --data '{
  "amount": 120000,
  "currency": "GBP",
  "remitter_provider_id": "ob-bank",
  "remitter_name": "Mike Smith",
  "remitter_sort_code": "987654",
  "remitter_account_number": "98765432",
  "remitter_reference": "FS-1000001",
  "beneficiary_name": "Financial Services Ltd",
  "beneficiary_sort_code": "234567",
  "beneficiary_account_number": "23456789"
  "beneficiary_reference": "FinServ-1a2b3c4d",
  "redirect_uri": "https://client.app.com/payment_redirect"
}' \
https://pay-api.truelayer.com/single-immediate-payments

The request will return a simp_id that you should store as, after authorisation, the user will be redirected to your redirect_uri with this appended as payment_id.

Use the auth_uri to redirect your user to authorise the payment.

{
  "results": [
    {
      "simp_id": "44708581-1967-4120-8f6a-1e532f1bf52a",
      "auth_uri": "https://example.com",
      "created_at": "2018-10-01T17:00:00.0000000+00:00",
      "amount": 120000,
      "currency": "GBP",
      "remitter_provider_id": "ob-bank",
      "remitter_name": "Mike Smith",
      "remitter_sort_code": "987654",
      "remitter_account_number": "98765432",
      "remitter_reference": "FS-1000001",
      "beneficiary_name": "Financial Services Ltd",
      "beneficiary_sort_code": "234567",
      "beneficiary_account_number": "23456789",
      "beneficiary_reference": "FinServ-1a2b3c4d",
      "redirect_uri": "https://client.app.com/payment_redirect",
      "status": "new"
    }
  ]
}

### Adapting an existing integration for EU payments (Private beta)

If you've already implemented the payments API and would now like to use our European payment capability, here are some key considerations to help you transition:

1. Instead of account numbers and sort codes, you need to use our IBAN fields.
2. Both the remitter and beneficiary IBANs are compulsory fields to create a payment with a European Bank in Euros.
3. You'll need to change the currency code to EUR.
4. European banks can only pay to European bank accounts.
5. Some banks have additional steps required (these appear on their provider in the providers endpoint result you get back) and you'll need to complete these steps before creating the payment and pre-fill the auth_inputs field.
6. The remitter provider ID is a compulsory field.
7. direct_bank_link is a compulsory field.

Redirecting your user to the bank

After creating the payment, you need to redirect the user to the auth_uri.

If you did not specify the remitter_provider_id your user will be redirected to the TrueLayer Provider Selection screen and from there on to their bank.

Handling a returning user

Once the payment is authorised, the user will return to your redirect_uri. The URL will include a payment_id query parameter containing the simp_id from the payment creation response.

https://client.app.com/payment_redirect?payment_id=a55f2e12-55ef-410c-9341-628033a62dc3

Managing payment status with webhooks

When the status of a payment changes, we send a single_immediate_payment_status_changed event to the uri that you specified when creating the payment.

In the header you will see the following fields:

In the body you will see the following fields:

Tl-Signature: "detached..jws"
X-TL-Webhook-Timestamp: 2020-05-18T10:17:52Z

{
  "event_type": "single_immediate_payment_status_changed",
  "event_body": {
    "payment_id": "77a75df0-af60-4785-8e91-809ac77ca8e3",
    "status": "executed"
  }
}

Webhook Retry Policy

We consider a webhook as having been successfully delivered when we receive a success status code (2xx) from your webhook URI.

If we receive any other status code (for instance, if your API is temporarily unavailable), we will start retrying. Our retry policy is jittered exponential backoff. We will immediately perform some fast retries and then start waiting increasingly longer. We will keep retrying for up to 72 hours.

Validate the received webhook signature

We recommend developers to use our signing libraries to verify the Tl-Signature of the received webhooks.

E.g. Java com.truelayer.truelayer-signing

Verifier.verifyWithJwks(jwks)
        .method("POST")
        .path(path)
        .headers(allWebhookHeaders)
        .body(body)
        .verify(webhookSignature);

Polling for payment status

The application can poll the payment resource to see if the status has been modified. This allows the application to know if the payment was successful or not.

Note that if the remitter was specified, remitter details will also be included in the response.

The payment resource may exist in different states according to the progress of the transaction:

• new: The payment resource has been created, but the payer has not yet authorised the payment. The initial API response will always have this status if the API call is successful.
• authorised: The payer has successfully authorised the payment using the bank portal, but the payment has not yet been submitted for execution.
• cancelled: The payer has cancelled the payment using the bank portal. This may also happen for some bank UIs if the payer clicks the “Back” button in their browser. This is a terminal state.
• failed: The bank has failed to initiate a payment session, this happens after a bank has been selected but before redirecting the user to the bank UI. This is a terminal state.
• rejected: The payer authorised the payment, but the bank rejected it after this. This is a terminal state.
• submitted: TrueLayer has successfully submitted the authorised payment initiation request to the bank API.
• executed: The funds have left the remitter’s account and will arrive in the beneficiary’s account. This is a terminal state.

The submitted and executed states are very close; in fact a bank may respond to the payment submission indicating the payment has already been executed. However, it is also possible for a payment to be queued within the bank for a short period of time; in that case, the payment status will initially be submitted, and then may be updated to executed after polling for a status check.

Note that after a payment has been executed, it may take some time for it to be settled, although for transactions executed via Faster Payments, this normally happens very quickly.

curl -H "Authorization: Bearer ${access_token}" \
https://pay-api.truelayer.com/single-immediate-payments/a55f2e12-55ef-410c-9341-628033a62dc3

{
  "results": [
    {
      "simp_id": "c45d38a6-2384-49aa-98ab-60134a50a5d7",
      "created_at": "2018-10-01T16:00:00.0000000+00:00",
      "amount": 350,
      "currency": "GBP",
      "beneficiary_reference": "ecommerce-12345",
      "beneficiary_name": "Ecommerce Shop",
      "beneficiary_sort_code": "102030",
      "beneficiary_account_number": "88881234",
      "remitter_reference": "ECOM-12345-ABCD",
      "redirect_uri": "http://www.ecommerce.com/redirect",
      "remitter_provider_id": "ob-lloyds",
      "status": "executed"
    }
  ]
}

To see all known states of your payment and trace your payment with the timestamps, add /statuses to the end of the request.

curl -H "Authorization: Bearer ${access_token}" \
https://pay-api.truelayer.com/single-immediate-payments/a55f2e12-55ef-410c-9341-628033a62dc3/statuses

{
    "results": [
        {
            "status": "New",
            "date": "2020-04-08T21:53:35.364038"
        },
        {
            "status": "Authorised",
            "date": "2020-04-08T21:54:17.690429"
        },
        {
            "status": "Submitted",
            "date": "2020-04-08T21:54:18.546706"
        },
        {
            "status": "Executed",
            "date": "2020-04-08T21:54:28.063325"
        },
        {
            "status": "Executed",
            "date": "2020-04-08T21:54:28.2761"
        }
    ],
    "status": "queued"
}

Testing Guidelines

The following guidelines aim to provide practical guidance while testing the integration.

Before testing with live accounts, we recommend that you test your integration with the sandbox. The Payments Quick Start provides instructions on how to access the sandbox APIs.

When you transition to live testing in the production environment:

1. Make sure you change all URIs to end with truelayer.com instead of truelayer-sandbox.com
2. Change from using your sandbox client_id_ and client_secret to your production client_id and client_secret. You can find your production client_id here: https://console.truelayer.com/settings/Application (you should have saved your production client_secret when you last reset it, or when you created your production account)
3. Have a live bank account to hand which you own to make payments from, as well as one to make payments into. The payer (or remitter) bank account must be from one of the supported providers listed here

Bank Account Limits

Each bank has its own limits on how much money can be transferred using online banking, which also apply to their open banking payment APIs.

Velocity Limits

All banks have controls in place to protect their end users from fraudulent withdrawals. One type of control is a velocity limit, which allows only a certain number of payments, or a maximum aggregate payment amount, per time period, for example, one hour, one day, and so on.

Banks will not publish these limits, as the information could be taken advantage of by fraudsters. Therefore, when testing:

• Do not make an excessive number of payments from the same account within a short time period.
• If it is not possible to make a successful payment, this will be visible in the bank’s authorisation user interface. At this point, it will be necessary to contact the specific bank’s end user support team to get the account unblocked.