Payment-method icon

Affirm for API only

Add Affirm to an existing API-only integration.

Accept Affirm payments using our APIs, and build your own payment form to have full control over the look and feel of your checkout page.

When making an Affirm payment, you also need to:

  1. Provide details about the items being purchased when making a payment request.
  2. Capture the payment after the transaction has been fulfilled. When the payment has been captured, Affirm starts the repayment period for the shopper.

Before you begin

Before starting your integration:

  1. Make sure that you have set up your back end implementation.
  2. Add Affirm in your test Customer Area.

Build your payment form for Affirm

To make an Affirm payment, you need to collect the following shopper details:

Name Description
firstName Shopper's first name.
lastName Shopper's last name.
telephoneNumber Shopper's phone number.
shopperEmail Shopper's email address.
billingAddress The address where to send the invoice.
deliveryAddress The address where the purchased goods should be delivered.

We provide an Affirm logo which you can use in your payment form. For more information, refer to Downloading logos.

Make a payment

From your server, make a /payments request, specifying:

Parameter name Required Description
paymentMethod.type -white_check_mark- Set to affirm.
shopperName.firstName -white_check_mark- Shopper's first name.
shopperName.lastName -white_check_mark- Shopper's last name.
telephoneNumber -white_check_mark- Shopper's telephone number.
shopperEmail -white_check_mark- Shopper's email address.
billingAddress -white_check_mark- The address where to send the invoice.
deliveryAddress The address where the purchased goods should be delivered. If blank or missing, billingAddress is used by default.
lineItems Price and product information about the purchased items. This is optional, but we recommend to include this data to improve approval rates.

In the /payments response, note the action object. This contains the information needed to redirect the shopper.

Handle the redirect

  1. To complete the payment, redirect the shopper to the action.url returned in the /payments response.

    When using the HTTP GET method:
    For security reasons, when displaying the redirect in the app, we recommend that you use SFSafariViewController for iOS or Chrome Custom Tabs for Android, instead of WebView objects. Also refer to the security best practices for WebView.

  2. After the shopper is redirected back to your website, check the payment result by making a POST /payments/details request, specifying:

    • details: object that contains the URL-decoded redirectResult returned when the shopper was redirected back to your site.
  3. In the response note the following:

    • resultCode: use this to present the result to your shopper.
    • pspReference: our unique identifier for the transaction.

Present the payment result

Use the  resultCode that you received in the /payments response to present the payment result to your shopper.

The resultCode values you can receive for Affirm are:

resultCode Description Action to take
Authorised The payment was successfully authorised. Inform the shopper that the payment was successful.
After the goods have been sent, you also need to capture the payment.
Cancelled The shopper cancelled the payment. Ask the shopper whether they want to continue with the order, or ask them to select a different payment method.
Pending The shopper has completed the payment but the final result is not yet known. Inform the shopper that you've received their order, and are waiting for the payment to be completed.
To know the final result of the payment, wait for the AUTHORISATION webhook.
Refused The payment was refused by Affirm. Ask the shopper to try the payment again using a different payment method.

Capture the payment

After the goods have been sent, you also need to capture the payment. All Affirm payments have to be manually captured, even if you have enabled automatic capture for other payment methods. Capturing the payment is what triggers the installment payment schedule for the shopper.

If for any reason you need to capture a lesser amount than what was authorised, you need to issue a refund for the difference after the capture. For example, a customer purchases two items of USD 500 each, totaling USD 1,000, but only one is fulfilled. After capturing USD 1,000, you should issue a subsequent refund for the unfulfilled item of USD 500.

Refunds and cancellations

If an Affirm payment hasn't been captured yet, you can cancel it. If the Affirm payment has already been captured and you want to return the funds to the shopper, you need to refund it.

Partial refunds

To partially refund an Affirm payment, specify in your /payments/{paymentPspReference}/refunds request:

  • modificationAmount: The amount to be refunded to the shopper.
  • additionalData.acquirerReference: The acquirerReference of the capture. This is needed if there are multiple partial captures available for the payment. When refunding in your Customer Area, you can add the acquirerReference manually as well.

The following example shows how to make a partial refund request if the shopper returned the shoes included in the original payment request.

Test and go live

To receive your test credentials, contact Affirm. After reviewing your test transactions, Affirm will provide you with the credentials for processing live transactions.

You can check the status of the test payments in your test Customer Area > Transactions > Payments.

Before you can accept live Affirm payments, you need to submit a request for Affirm in your live Customer Area, and provide us with your Affirm live credentials.

See also