Tokenizing a card in a mobile app

Use the flexible ProcessOut UI to collect card details or build your own form.

Once you have an invoice for a payment, the next step is usually to generate a payment source token to
represent the customer's payment details. The most common example of a payment source is a card token. (See the page about accepting card payments) to learn more about card tokens and their place in the payment flow.)

We provide client-side SDKs for iOS and Android. These let you generate a card token directly from a customer's details as described below. You can also use our SDKs to accept payment with Apple Pay and Google Pay, which are described separately.

Tokenization UI

The ProcessOut mobile SDKs offer pre-built, customizable forms that you can embed in your app. They allow you to control the look and feel of the interface while keeping your integration simple.

Tokenization UI example on iOS

Tokenization UI example on iOS

Integrating the tokenization UI

First, you should obtain and set up the SDK in your code using the instructions for iOS or Android, as appropriate.

We offer a UI to facilitate card tokenization. For SwiftUI users, there is POCardTokenizationView, which provides an interface for users to enter their card details. If you are using UIKit, we provide POCardTokenizationViewController.

The creation process for both is similar, with the key difference being that you must pass the style during initialization for the UIKit version, as it cannot be set later.

The Android SDK provides POCardTokenizationLauncher to start the activity.

import ProcessOutUI

POCardTokenizationView { result in
    switch result {
    case .success(let card):
        // todo: handle tokenized card
    case .failure(let failure):
        // todo: handle tokenization failure
// 1) Initialize the launcher in the onCreate() method of your Activity or Fragment.

private lateinit var launcher: POCardTokenizationLauncher

override fun onCreate(savedInstanceState: Bundle?) {
    launcher = POCardTokenizationLauncher.create(from = this) { result ->
        result.onSuccess { card ->
            // Handle the tokenized card.
        }.onFailure { failure ->
            // Handle the tokenization failure.

// 2) Launch the activity.


After the tokenization is complete, the view calls a completion handler you passed when creating it with the card object or failure if the implementation was unable to recover from failure.


The view accepts a configuration that allows you to customize the information collected. Configuration options include:

  • Whether to collect the cardholder's name.
  • The title displayed on the screen.
  • The title of the tokenize button.
  • Whether the user can manually cancel the flow and the title of the cancel button.
  • Metadata to be assigned to the card token.

Check the SDK reference for iOS and Android. The example below shows how to create and pass this configuration.

let configuration = POCardTokenizationConfiguration(
  isCardholderNameInputVisible: false,
  primaryActionTitle: "Continue",
  cancelActionTitle: "", // Hides cancel button
  metadata: ["key": "value"]

/// Create view with custom configuration
POCardTokenizationView(configuration: configuration) { result in ... }
    title = "Add New Card",
    isCardholderNameFieldVisible = true,
    billingAddress = POCardTokenizationConfiguration.BillingAddressConfiguration(
        // Configure how to collect the billing address.
    primaryActionText = "Submit",
    secondaryActionText = "Cancel",
    cancellation = POCancellationConfiguration(
        secondaryAction = true,
        backPressed = false,
        dragDown = true,
        touchOutside = false
    metadata = null, // Metadata related to the card.
    style = POCardTokenizationConfiguration.Style(
        // Customize the look and feel.

Billing address configuration

The billing address configuration is part of the overall configuration when creating the view. You can set the collection preference using the mode property, with the following options:

  • Automatic: The implementation automatically decides what information is needed.
  • Never: No billing info is collected.
  • Full: As much details as possible are collected.

You can also limit the supported countries that the user can select from by setting the countryCodes property.

If you know the customer's billing address in advance, you can set the defaultAddress. When this is set, and the collection mode is other than never, the customer can modify the default address.

The attachDefaultsToPaymentMethod property can be set to true if you want the implementation to fill in any fields the user didn't enter with defaults. This is especially useful in combination with the never collection mode to set an address during tokenization without allowing the user to change it.


The SDK automatically adjusts the collected billing address details based on the selected country, including the collected fields and their names.

Check the SDK reference for iOS and Android and example below for additional details.

let addressConfiguration = POBillingAddressConfiguration(
  mode: .automatic,
  countryCodes: ["GB", "US"],
  defaultAddress: .init(zip: "M44 5YN", countryCode: "GB")
let configuration = POCardTokenizationConfiguration(billingAddress: addressConfiguration)
    billingAddress = BillingAddressConfiguration(
        mode = CollectionMode.Automatic,
        countryCodes = setOf("GB", "US"),
        defaultAddress = POContact(
            countryCode = "GB",
            zip = "M44 5YN"

Card post-processing on iOS

To not only tokenize the card but to additionally process it before view completes, pass a delegate that implements the processTokenizedCard method.

For example, you can assign the tokenized card to a specific customer token for future invoice authorizations. This flow would look like this:

func processTokenizedCard(card: POCard) async throws {
  // Call your backend to create a customer and customer token, if not previously done.
  let request = POAssignCustomerTokenRequest(
    customerId: "cust_otbTu8aabNSAntSVZuqXCKScltFtxo1h",
    tokenId: "tok_UGimEkEqkv1Dr1gZV3G5U68z7xlF0HVo",
  let customerTokensService = ProcessOut.shared.customerTokens
  try await customerTokensService.assignCustomerToken(request: request, threeDSService: threeDSService)

In addition to mentioned above delegate can be also used to:

  • Change the preferred scheme if multiple schemes are available.
  • Observe events to gain insights into user actions.
  • Decide whether the user should be able to continue when certain error occurs.

Please refer to delegate reference for additional information.

Card post-processing on Android

Communication with the card tokenization activity is facilitated via POCardTokenizationEventDispatcher. To process the tokenization result before the activity completes, subscribe to processTokenizedCard flow and notify when processing is complete.

For example, you can assign the tokenized card to a specific customer token for future invoice authorizations. This flow would look like this:

// 1) Subscribe to additionally process tokenized card before completion (e.g. assign customer token).

lifecycleScope.launch {
        .processTokenizedCard.collect { card ->
            // Call your backend to create a customer and customer token, if not previously done.
                request = POAssignCustomerTokenRequest(
                    customerId = "cust_otbTu8aabNSAntSVZuqXCKScltFtxo1h",
                    tokenId = "tok_UGimEkEqkv1Dr1gZV3G5U68z7xlF0HVo",
                    source =
                threeDSService = create3DSService()

// 2) Once you've subscribed it's required to call [complete] after processing.

lifecycleScope.launch {
        .assignCustomerTokenResult.collect { result ->

In addition to mentioned above dispatcher can be also used to:

  • Alter the preferred scheme if multiple schemes are available.
  • Observe events to gain insights into user actions.
  • Decide whether user should be able to continue when certain error occurs.


To additionally customize the UI on iOS you should create a custom style and provide it when creating POCardTokenizationViewController for UIKit, or with the cardTokenizationStyle method for SwiftUI.

You can pass a custom style in the configuration on Android. Check the SDK reference for more information.

let style = POCardTokenizationStyle(
  title: .init(
    color: .black, typography: .init(font: .systemFont(ofSize: 14))

POCardTokenizationView { _ in }.cardTokenizationStyle(style)
    style = POCardTokenizationConfiguration.Style(
        title = POTextStyle(
            colorResId = R.color.text_primary,
            type = POTextType(
                textSizeSp = 20,
                lineHeightSp = 28,
                weight = POTextType.Weight.MEDIUM
        // ...

API bindings

For a more customizable approach, use our API bindings directly to tokenize a card.

The code sample below shows how to tokenize a set of card details that you have already received from the customer (you can use any suitable UI to do this). The token itself is just a string value that represents the card for this particular payment.

// First, create a tokenization request with card details. Check `init` for
// additional parameters that could be passed when creating a request.
let tokenizationRequest = POCardTokenizationRequest(
    number: "4242424242424242", expMonth: 04, expYear: 30, cvc: "737"

// Send request. tokenizationRequest) { result in
    switch result {
    case .success(let card):
        // Send to your backend to charge a customer.
    case .failure(let failure):
        // Inspect `failure.code` for the detailed error reason.

// Alternatively, use an async method.
let card = try await tokenizationRequest)
val tokenizationRequest = POCardTokenizationRequest(
    number = "4242424242424242",
    expMonth = 4,
    expYear = 30,
    cvc = "737"

// Coroutine function { result ->
    when (result) {
        // Send the card ID to your backend to charge a customer.
        is ProcessOutResult.Success ->
        // Inspect POFailure.Code for the detailed error reason.
        is ProcessOutResult.Failure -> result.code

// Callback function
    request = tokenizationRequest,
    callback = object : ProcessOutCallback<POCard> {
        override fun onSuccess(result: POCard) {
            // Send the card ID to your backend to charge a customer.

        override fun onFailure(
            code: POFailure.Code,
            message: String?,
            invalidFields: List<POFailure.InvalidField>?,
            cause: Exception?
        ) {
            // Inspect POFailure.Code for the detailed error reason.

What’s Next

Once you have generated the card token successfully, you can use it to process a payment. For Cardholder Initiated Transactions, you will first need to authorize the payment on the client before capturing it on the server. You may also be interested in saving the token to capture future payments.