Accept a Sofort payment

First, you need a Stripe account. Register now.

Server-side

This integration requires endpoints on your server that talk to the Stripe API. Use the official libraries for access to the Stripe API from your server:

# Available as a gem
sudo gem install stripe

# If you use bundler, you can add this line to your Gemfile
gem 'stripe'

Client-side

The Stripe iOS SDK is open source, fully documented, and compatible with apps supporting iOS 13 or above.

Configure the SDK with your Stripe publishable key on app start. This enables your app to make requests to the Stripe API.

import UIKit
import StripePaymentsUI

@main
class AppDelegate: UIResponder, UIApplicationDelegate {

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        StripeAPI.defaultPublishableKey = 
"pk_test_TYooMQauvdEDq54NiTphI7jx"
        // do any other necessary launch configuration
        return true
    }
}

A PaymentIntent represents your intent to collect payment from a customer and tracks the lifecycle of the payment process.

Server-side

Create a PaymentIntent on your server and specify the amount to collect and the eur currency (Sofort doesn’t support other currencies). If you have an existing Payment Intents integration, add sofort to the list of payment method types.

curl https://api.stripe.com/v1/payment_intents \
  -u "
sk_test_BQokikJOvBiI2HlWgH4olfQ2
:" \
  -d amount=1099 \
  -d currency=eur \
  -d "payment_method_types[]"=sofort

Changing the preferred language

By default, Stripe presents the Sofort authorization page in a language based on the specified country code. You can customize this to the language preferred by your customer by specifying it as part of the request and changing the value of the preferred_language property. The supported values are de, en, es, it, fr, nl, and pl.

curl https://api.stripe.com/v1/payment_intents \
  -u "
sk_test_BQokikJOvBiI2HlWgH4olfQ2
:" \
  -d amount=1099 \
  -d currency=eur \
  -d "payment_method_types[]"=sofort \
  -d "payment_method_options[sofort][preferred_language]"=de

Instead of passing the entire PaymentIntent object to your app, return its client secret. The PaymentIntent’s client secret is a unique key that lets you confirm the payment and update payment details on the client, without allowing manipulation of sensitive information, like payment amount.

Client-side

On the client, request a PaymentIntent from your server and store its client secret.

class CheckoutViewController: UIViewController {
var paymentIntentClientSecret: String?

func startCheckout() {
  // Request a PaymentIntent from your server and store its client secret
}
}

When a customer taps to pay with Sofort, confirm the PaymentIntent to complete the payment. Configure a STPPaymentIntentParams object with the PaymentIntent client secret from your server. Sofort requires that you collect the country code of your customer’s bank and pass it in the STPPaymentMethodSofortParams.

Rather than sending the entire PaymentIntent object to the client, use its client secret. This is different from your API keys that authenticate Stripe API requests. The client secret is a string that lets your app access important fields from the PaymentIntent (for example, status) while hiding sensitive ones (for example, customer).

Set up a return URL

The iOS SDK can present a webview in your app to complete the Sofort payment. When authentication is finished, the webview can automatically dismiss itself instead of having your customer close it. To enable this behavior, configure a custom URL scheme or universal link and set up your app delegate to forward the URL to the SDK.

// This method handles opening custom URL schemes (for example, "your-app://stripe-redirect")
func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey: Any] = [:]) -> Bool {
    let stripeHandled = StripeAPI.handleURLCallback(with: url)
    if (stripeHandled) {
        return true
    } else {
        // This was not a Stripe url – handle the URL normally as you would
    }
    return false
}

// This method handles opening universal link URLs (for example, "https://example.com/stripe_ios_callback")
func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([UIUserActivityRestoring]?) -> Void) -> Bool {
    if userActivity.activityType == NSUserActivityTypeBrowsingWeb {
        if let url = userActivity.webpageURL {
            let stripeHandled = StripeAPI.handleURLCallback(with: url)
            if (stripeHandled) {
                return true
            } else {
                // This was not a Stripe url – handle the URL normally as you would
            }
        }
    }
    return false
}

Call STPPaymentHandler confirmPayment to complete the payment.

let paymentIntentParams = STPPaymentIntentParams(clientSecret: paymentIntentClientSecret)

let sofort = STPPaymentMethodSofortParams()
sofort.country = "DE"

paymentIntentParams.paymentMethodParams = STPPaymentMethodParams(sofort: sofort, billingDetails: nil, metadata: nil)

paymentIntentParams.returnURL = "payments-example://stripe-redirect"
STPPaymentHandler.shared().confirmPayment(paymentIntentParams, with: self) { (handlerStatus, paymentIntent, error) in
    switch handlerStatus {
    case .succeeded:
        // Payment succeeded
        // ...

    case .canceled:
        // Payment canceled
        // ...

    case .failed:
        // Payment failed
        // ...

    @unknown default:
        fatalError()
    }
}

As Sofort is a delayed notification payment method, the PaymentIntent’s status remains in a payment_intent.processing state for up to 14 days from its creation (also known as the cutoff date). In a sandbox, the PaymentIntent’s status remains in the processing state for three minutes to simulate this.

• Stripe recommends fulfilling purchases during the processing state. On average, you can expect approximately 0.2% of Sofort payment attempts to fail after entering the processing state. This only applies to Sofort payments due to its low payment failure rate and doesn’t apply to other delayed notification payment methods.
• You may prefer to fulfil orders only after receiving the payment_intent.succeeded event. Stripe sends this event after the payment attempt is confirmed and the funds are guaranteed.
• If a customer doesn’t pay, Stripe sends the payment_intent.failed event and the PaymentIntent returns to a status of requires_payment_method.

Use the Dashboard, a custom webhook, or a partner solution to receive these events and run actions, like sending an order confirmation email to your customer, logging the sale in a database, or starting a shipping workflow.

Manually

Use the Stripe Dashboard to view all your Stripe payments, send email receipts, handle payouts, or retry failed payments.

• View your test payments in the Dashboard

Custom code

Build a webhook handler to listen for events and build custom asynchronous payment flows. Test and debug your webhook integration locally with the Stripe CLI.

• Build a custom webhook

Prebuilt apps

Handle common business events, like automation or marketing and sales, by integrating a partner application.