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 test 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.

1
import SumUpSDK
2

3
@main
4
class AppDelegate: UIResponder, UIApplicationDelegate {
5
    func application(
6
        _ application: UIApplication,
7
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
8
    ) -> Bool {
9
        SumUpSDK.setup(withAPIKey: "sup_afk_abcqwerty")
10
        return true
11
    }
12
}

1
public class SampleApplication extends Application {
2
  @Override
3
  public void onCreate() {
4
    super.onCreate();
5
    SumUpState.init(this);
6
  }
7
}

2. Authenticate

iOS
Android

1
SumUpSDK.presentLogin(from: self, animated: true) { success, error in
2
    if let error {
3
        print("Login error: \(error)")
4
        return
5
    }
6

7
    if success {
8
        print("Merchant logged in")
9
    }
10
}

1
SumUpLogin login = SumUpLogin.builder("sup_afk_abcqwerty").build();
2
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

1
SumUpSDK.prepareForCheckout()

1
SumUpAPI.prepareForCheckout();

4. Start a Payment

iOS
Android

1
guard let merchantCurrencyCode = SumUpSDK.currentMerchant?.currencyCode else {
2
    return
3
}
4

5
let request = CheckoutRequest(
6
    total: NSDecimalNumber(string: "12.34"),
7
    title: "Coffee",
8
    currencyCode: merchantCurrencyCode
9
)
10
request.foreignTransactionID = UUID().uuidString
11

12
SumUpSDK.checkout(with: request, from: self) { result, error in
13
    if let error {
14
        print("Checkout error: \(error)")
15
        return
16
    }
17

18
    if let result {
19
        print("Result: \(result.success), transactionCode: \(result.transactionCode ?? "-")")
20
    }
21
}

1
SumUpPayment payment = SumUpPayment.builder()
2
    .total(new BigDecimal("12.34"))
3
    .currency(SumUpPayment.Currency.EUR)
4
    .title("Coffee")
5
    .foreignTransactionId(UUID.randomUUID().toString())
6
    .build();
7

8
SumUpAPI.checkout(this, payment, 2);

5. Handle the Checkout Result

iOS
Android

1
// Handled in the completion block of SumUpSDK.checkout(...)
2
// Use result.success, result.transactionCode, and error for your UI/state updates.

1
@Override
2
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
3
  super.onActivityResult(requestCode, resultCode, data);
4
  if (requestCode == 2 && data != null) {
5
    int code = data.getExtras().getInt(SumUpAPI.Response.RESULT_CODE);
6
    String message = data.getExtras().getString(SumUpAPI.Response.MESSAGE);
7
    String txCode = data.getExtras().getString(SumUpAPI.Response.TX_CODE);
8
    // Update your UI/state here.
9
  }
10
}