Accept payments

A unified quickstart for accepting card-reader payments with the iOS or Android Terminal SDK.

This guide shows the core card-reader payment flow for both mobile SDKs.

For platform-specific setup details, permissions, and advanced options, use the full documentation:

iOS Terminal SDK
Android Reader SDK
Android Tap-to-Pay SDK (phone-based contactless payments without a separate reader)

Prerequisites

A SumUp merchant account (or sandbox merchant account).
An Affiliate Key linked to your app.
A compatible card reader paired with the merchant account.

Basic Payment Flow

Initialize the SDK with your Affiliate Key.
Log the merchant in.
Optionally prepare the reader connection before checkout.
Create a checkout request and start payment.
Handle the result in your app.

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import SumUpSDK
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@main
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class AppDelegate: UIResponder, UIApplicationDelegate {
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    func application(
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        _ application: UIApplication,
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        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
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    ) -> Bool {
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        SumUpSDK.setup(withAPIKey: "sup_afk_abcqwerty")
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        return true
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    }
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}

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public class SampleApplication extends Application {
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  @Override
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  public void onCreate() {
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    super.onCreate();
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    SumUpState.init(this);
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  }
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}

2. Authenticate

iOS
Android

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SumUpSDK.presentLogin(from: self, animated: true) { success, error in
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    if let error {
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        print("Login error: \(error)")
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        return
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    }
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    if success {
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        print("Merchant logged in")
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    }
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}

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SumUpLogin login = SumUpLogin.builder("sup_afk_abcqwerty").build();
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SumUpAPI.openLoginActivity(this, login, 1);

3. Prepare for Checkout (Optional)

Use this when the merchant is about to charge, so the SDK can wake/reconnect the reader early.

iOS
Android

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SumUpSDK.prepareForCheckout()

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SumUpAPI.prepareForCheckout();

4. Start a Payment

iOS
Android

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guard let merchantCurrencyCode = SumUpSDK.currentMerchant?.currencyCode else {
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    return
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}
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let request = CheckoutRequest(
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    total: NSDecimalNumber(string: "12.34"),
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    title: "Coffee",
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    currencyCode: merchantCurrencyCode
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)
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request.foreignTransactionID = UUID().uuidString
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SumUpSDK.checkout(with: request, from: self) { result, error in
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    if let error {
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        print("Checkout error: \(error)")
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        return
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    }
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    if let result {
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        print("Result: \(result.success), transactionCode: \(result.transactionCode ?? "-")")
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    }
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}

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SumUpPayment payment = SumUpPayment.builder()
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    .total(new BigDecimal("12.34"))
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    .currency(SumUpPayment.Currency.EUR)
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    .title("Coffee")
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    .foreignTransactionId(UUID.randomUUID().toString())
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    .build();
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SumUpAPI.checkout(this, payment, 2);

5. Handle the Checkout Result

iOS
Android

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// Handled in the completion block of SumUpSDK.checkout(...)
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// Use result.success, result.transactionCode, and error for your UI/state updates.

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@Override
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protected void onActivityResult(int requestCode, int resultCode, Intent data) {
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  super.onActivityResult(requestCode, resultCode, data);
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  if (requestCode == 2 && data != null) {
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    int code = data.getExtras().getInt(SumUpAPI.Response.RESULT_CODE);
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    String message = data.getExtras().getString(SumUpAPI.Response.MESSAGE);
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    String txCode = data.getExtras().getString(SumUpAPI.Response.TX_CODE);
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    // Update your UI/state here.
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  }
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}