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SumUp SumUp Developer

iOS

Integrate the Payment Switch on iOS by opening the SumUp URL scheme and parsing the callback in your app.

The iOS Payment Switch starts a payment by opening the SumUp app with a URL scheme. After the checkout completes, the SumUp app redirects back to your app with the payment result.

Prerequisites

  • A valid Affiliate Key associated with your iOS bundle identifier.
  • The SumUp app installed on the device.
  • A custom URL scheme registered by your app to receive callbacks.

Integration Steps

  1. Register a callback URL scheme.

    In Xcode, add a URL type for your app, for example myapp. That gives you a callback URL such as myapp://sumup-callback.

  2. Open the SumUp app.

    Use URLComponents to build the Payment Switch request and open the SumUp app:

    let foreignTxId = UUID().uuidString

var components = URLComponents(string: "sumupmerchant://pay/1.0")!
components.queryItems = [
    URLQueryItem(name: "amount", value: "12.34"),
    URLQueryItem(name: "currency", value: "EUR"),
    URLQueryItem(name: "affiliate-key", value: "YOUR_AFFILIATE_KEY"),
    URLQueryItem(name: "title", value: "Coffee"),
    URLQueryItem(name: "receipt-email", value: "customer@example.com"),
    URLQueryItem(name: "receipt-mobilephone", value: "+49123456789"),
    URLQueryItem(name: "foreign-tx-id", value: foreignTxId),
    URLQueryItem(name: "callbacksuccess", value: "myapp://sumup-callback"),
    URLQueryItem(name: "callbackfail", value: "myapp://sumup-callback"),
    URLQueryItem(name: "skip-screen-success", value: "true"),
]

if let paymentURL = components.url {
    UIApplication.shared.open(paymentURL)
}

    The mandatory parameters are amount, currency, and affiliate-key. The callback URLs tell the SumUp app where to return after success or failure.

  3. Handle the callback.

    Parse the callback URL and inspect the query parameters when your app is reopened:

    func scene(
    _ scene: UIScene,
    openURLContexts URLContexts: Set<UIOpenURLContext>
) {
    guard let url = URLContexts.first?.url,
          let components = URLComponents(url: url, resolvingAgainstBaseURL: false) else {
        return
    }

    let queryItems = Dictionary(
        uniqueKeysWithValues: components.queryItems?.map { ($0.name, $0.value ?? "") } ?? []
    )

    let status = queryItems["smp-status"]
    let transactionCode = queryItems["smp-tx-code"]
    let foreignTxId = queryItems["foreign-tx-id"]

    if status == "success" {
        // Mark the order as paid and persist transactionCode / foreignTxId.
    } else {
        // Show the failure state and allow retry.
    }
}

    When available, the callback can include:

    • smp-status: success, failed, or invalidstate
    • smp-tx-code: The SumUp transaction code
    • foreign-tx-id: The external transaction ID you sent with the request

Common Parameters

  • title: Optional label shown in transaction history and receipts.
  • receipt-email: Prefills the email receipt field in the SumUp app.
  • receipt-mobilephone: Prefills the SMS receipt field in the SumUp app.
  • foreign-tx-id: Your unique external transaction reference. Keep it unique per payment and under 128 characters.
  • skip-screen-success=true: Skips the success screen after a successful payment. Use this only if your app shows the final payment outcome itself.

Notes

  • The payment currency must match the currency of the merchant account logged in to the SumUp app.
  • Use the same callback URL for both success and failure if you want a single result handler in your app.
  • The official iOS repository also provides an SMPPaymentRequest helper if you prefer not to build the URL manually.