**Last updated**: 30 October 2025 | [**Change log**](/access/products/checkout/ios/changelog/) # Card Validation Validate your customer's card details before processing them. Warning The validation does not check if your customer's card details are correct. The validation only checks the format of the entered details. ## Get started * you have added the `AccessCheckoutSDK` to your project as a Cocoapods dependency * you have added an `import AccessCheckoutSDK` at the top of your swift file The four basic components for this integration are: * Your UITextField's for PAN, expiry date and CVC * An `AccessCheckoutCardValidationDelegate` is designed to receive events pertaining to validation * An instance of `CardValidationConfig` contains all the information required for the initialization of the validation flow, including references to the view components to enable validation for * An `AccessCheckoutValidationInitialiser` is responsible for initializing the validation flow Full Sample Integration You can see an example of the CVC validation integration [here](https://github.com/Worldpay/access-checkout-ios/tree/v2.4.1/AccessCheckoutDemo). ## Create and reference the UI components To display your checkout form, you must create your layout first using your storyboard. Here's an example of how you would reference your UI components using unique identifiers. ```swift import AccessCheckoutSDK class ViewController: UIViewController { @IBOutlet weak var panTextField: UITextField! @IBOutlet weak var expiryDateTextField: UITextField! @IBOutlet weak var cvcTextField: UITextField! ... ``` ## Implement the `AccessCheckoutCardValidationDelegate` protocol This ensures you are notified of validation events and card brand changes on customer input. Here's an example. ```swift extension ViewController: AccessCheckoutCardValidationDelegate { // This event handler is notified when the card brand detected by the SDK has changed func cardBrandChanged(cardBrand: CardBrand?) { // This piece of code updates in the UI a card image displayed in a UIImageView next to the PAN // A cardBrand contains a name and an array of images objects. // Each image object has a URL and a type (either image/png or image/svg+xml) and represents the same brand if let imageUrl = cardBrand?.images.filter({ $0.type == "image/png" }).first?.url, let url = URL(string: imageUrl) { DispatchQueue.global(qos: .userInteractive).async { if let data = try? Data(contentsOf: url) { DispatchQueue.main.async { self.imageView.image = UIImage(data: data) } } } } else { // This occurs when the SDK has not been able to identify the card brand from the PAN entered by the customer self.imageView.image = ... } } // This event handler is notified when the PAN becomes valid or invalid func panValidChanged(isValid: Bool) { // You might want to change the text color panTextField.textColor = isValid ? nil : UIColor.red if !valid { // You might want to disable a submit button which would normally be clicked on when all fields are valid submitButton.isEnabled = false } } // This event handler is notified when the CVC becomes valid or invalid func cvcValidChanged(isValid: Bool) { // You might want to change the text color cvcTextField.textColor = isValid ? nil : UIColor.red if !valid { // You might want to disable a submit button which would normally be clicked on when all fields are valid submitButton.isEnabled = false } } // This event handler is notified when the expiry date becomes valid or invalid func expiryDateValidChanged(isValid: Bool) { // You might want to change the text color expiryDateTextField.textColor = isValid ? nil : UIColor.red if !valid { // You might want to disable a submit button which would normally be clicked on when all fields are valid submitButton.isEnabled = false } } // This event handler is notified when the PAN, expiry date and CVC are all valid func validationSuccess() { // You might want to enable a submit button when all fields are valid submitButton.isEnabled = true } } ``` ## Instantiate a `CardValidationConfig` and initialize the validation We highly recommend to do this in the `viewDidLoad()` handler of your UIViewController. This is because the `AccessCheckoutValidationInitialiser` asynchronously requests a file containing validation configuration. ```swift override func viewDidLoad() { ... let validationConfig = try! CardValidationConfig.builder() .pan(panTextField) .expiryDate(expiryDateTextField) .cvc(cvcTextField() .accessBaseUrl() .validationDelegate(self) .build() AccessCheckoutValidationInitialiser().initialise(validationConfig) } ``` | Placeholder | Descriptions | | --- | --- | | `` | For testing use: `https://try.access.worldpay-bsh.securedataplatform.com/`For live use: `https://access.worldpay-bsh.securedataplatform.com/` | #### Card validation rules The validation logic in the SDK, is based off a set of default rules for any card type. Specific brand rules are fetched from a `CardTypes` JSON file, which holds the validation rules and card brand logos for each brand. The icons are available in both `SVG` and `PNG`. #### Validation rules The table below shows the rules that our SDK uses to validate your customer's card details. | Card Name | BIN Range | PAN Length | CVC Length | | --- | --- | --- | --- | | Amex | 34, 37 | 15 | 4 | | Diners | 300-305, 3095, 36, 38, 39 | 14, 16, 19 | 3 | | Discover | 6011, 644 - 649, 65 | 16, 19 | 3 | | JCB | 2131, 1800, 3088 - 3094, 3096 - 3102, 3112 - 3120, 3158 - 3159, 3337 - 3349, 3528 - 3589 | 16, 17, 18, 19 | 3 | | Maestro | 493698, 500000 - 506698, 506779 - 508999, 56 - 59, 63, 67, 6 | 12, 13, 14, 15, 16, 17, 18, 19 | 3 | | MasterCard | 51 - 55, 2221 - 2229, 223 - 229, 23 - 26, 270 - 271, 2720: optimized using 22 - 27 | 16 | 3 | | Visa | 4 | 13, 16, 18, 19 | 3 | ## Card brand restriction The SDK enables you to optionally provide a list of card brands that you support. This means that if you do not support a certain card brand, the SDK notifies your code of an invalid PAN if an unsupported brand is recognized. By default, the SDK allows cards from any brand. If you do not wish to restrict the card brands that you accept then you do not need to pass any configuration. #### Example Configuration To restrict the card brands that you accept, simply pass in an array of the brands that you **do** wish to accept when initializing the SDK. The following validation configuration restricts the SDK to accept only American Express, Visa or Mastercard BIN ranges. ```swift let validationConfig = try! CardValidationConfig.builder() ... .acceptedCardBrands(["visa", "mastercard", "AMEX"]) ... .build() ``` #### Currently supported card brands The SDK is able to recognize the following card brands: | Brand | Code | | --- | --- | | American Express | `"amex"` | | Diners | `"diners"` | | Discover | `"discover"` | | JCB | `"jcb"` | | Maestro | `"maestro"` | | Mastercard | `"mastercard"` | | Visa | `"visa"` | Note If the SDK does not recognize a PAN as one of the above brands, it will be permitted as long as it meets the usual criteria for a valid PAN. ## PAN formatting The SDK allows PAN formatting as the customer types. This feature is disabled by default. The PAN is formatted in the following way: | Card Type | Formatting | | --- | --- | | Visa, Mastercard, JCB, Discover, Diners, Maestro | XXXX XXXX XXXX XXXX | | Amex | XXXX XXXXXX XXXXX | #### Enabling PAN formatting To enable the PAN formatting behavior, simply call the `enablePanFormatting` method on the builder. ```swift let validationConfig = try! CardValidationConfig.builder() ... .enablePanFormatting() ... .build() ``` ### Create session(s) Once validation is in place you can request `sessions` to implement your payment flow. **Next steps** [Create a session to pay with a card](/access/products/checkout/ios/v2/card-only) or [Create sessions to pay with a card and cvc](/access/products/checkout/ios/v2/card-and-cvc)