What is 3DS?

Strong Customer Authentication (SCA) regulation in Europe requires the use of 3D Secure (3DS) for card payments.

3DS requires customers to complete an additional verification step with the card issuer when paying. If challenged, we direct the customer to an authentication page served by their bank, and they enter a password associated with the card or a code sent to their phone.

Configure 3D Secure for your Primer account

At Primer, we've decoupled 3D Secure from any underlying processor. Configure 3D Secure in your workflow, and Universal Checkout will handle the rest, presenting a fully in-context and optimized 3D Secure flow to your customer on web and mobile. Now you're SCA-ready with a unified checkout across all your payments services including 3D Secure 2.0.

Primer supports Dynamic 3DS to improve conversion, enabling you to present 3D Secure to customers only when it's absolutely required.

If your card processor does not support third-party 3D Secure, Primer seamlessly redirects the user to the processor's 3DS challenge page instead.

Set up the workflow for 3D Secure

Configuring 3DS settings for your payments takes place within the "Authorize payment" Action. Learn more here about how to set up a workflow to process payments.

Example of setting up a workflow

In the configuration panel, you need to choose which 3DS option you want for all payments processed by this Action block:


No 3DS

3D Secure will not be used for any payments processed by this block. Payments will be declined when the Issuer requires authentication.


Adaptive 3DS

Use Primer’s proprietary Adaptive 3DS which will only carry out 3DS authentication if the payment would be declined without it.


Primer 3DS

3D Secure authentication will be handled by Primer's agnostic 3D Secure solution for payments processed by this block. This could either be a challenge or frictionless.


Processor 3DS

Your processor will present a 3DS challenge according to their configuration. This isn't compatible with Fallbacks as Primer is not involved in the flow.

Configure your Client Session

To improve 3DS success rates, it is recommended to pass the following elements in the Client Session:

  1. customer
The customer's email address
  1. customer
The customer's billing address

In Sandbox, the email address and billing address must be provided to trigger 3DS.

Handle 3D Secure in Universal Checkout

Install Primer3DS SDK

3D Secure on iOS requires the addition of the Primer3DS library to your project.

With CocoaPods

First, modify your Podfile like so:

source 'https://github.com/CocoaPods/Specs.git'source 'https://github.com/primer-io/primer-podspecs.git' use_frameworks! target 'PrimerSDK_Example' do  pod 'PrimerSDK'  pod 'Primer3DS'    // ...end

Then run pod install to install Primer3DS on your workspace.

In case you encounter an error that the bundle needs signing on Xcode 14, add the following post-install script in your podfile.

post_install do |installer|  installer.pods_project.targets.each do |target|    if target.respond_to?(:product_type) and target.product_type == "com.apple.product-type.bundle"      target.build_configurations.each do |config|          config.build_settings['CODE_SIGNING_ALLOWED'] = 'NO'      end    end  endend

In case you notice the warning "WARNING! Failed to import Primer3DS" when you initialize the PrimerSDK, add the following post-install script in the end of your pod file.

target 'MyApp' do  pod 'PrimerSDK'  pod 'Primer3DS'   # ...   # This is what needs to be added  post_install do |installer|    installer.pods_project.targets.each do |target|      if target.name == "PrimerSDK"        target.build_configurations.each do |config|          config.build_settings['OTHER_LDFLAGS'] = '$(inherited) -framework "Primer3DS"'        end      end    end  endend
With Swift Package Manager

To add PrimerSDK with Swift Package Manager;

  1. 1
    Select your project, and then navigate to Package Dependencies
  2. 2
    Click on the + button at the bottom-left of the Packages section
  3. 3
    Paste https://github.com/primer-io/primer-sdk-3ds-ios into the Search Bar
  4. 4
    Press Add Package
  5. 5
    Let Xcode download the package and set everything up

Adding Primer 3DS


If Primer3DS is not installed, 3DS will fail. In the case of a 3DS triggered by the workflow, the primerDidFailWithError functions will be called.

Handle Out-of-Band (OOB) redirects (Optional)

Starting from 3D Secure protocol version 2.2.0, you can enhance the user experience by implementing an automatic redirect from another (authentication) application during an OOB challenge to your application once the challenge is successfully completed. This feature allows for a seamless transition and improved user flow.


If this feature is not implemented, the user will have to come back to your application manually to complete their payment, which adds significant friction.

To enable this feature, ensure that you include the threeDsAppRequestorUrl parameter when configuring the PrimerThreeDsOptions object.

Please note that the threeDsAppRequestorUrl value must be an iOS Universal Link. Additionally, it is essential that your application is configured to handle the Universal Link properly in order to facilitate the redirection.

To configure the Universal Link correctly using Universal Checkout, follow these steps:

  1. 1

    Pass your Universal Link (e.g. https://{UNIVERSAL_LINK}) as threeDsAppRequestorUrl in the PrimerThreeDsOptions object of your settings.

    let settings = PrimerSettings(  // ...  paymentMethodOptions: PrimerPaymentMethodOptions(    threeDsOptions: PrimerThreeDsOptions(      threeDsAppRequestorUrl: "https://{UNIVERSAL_LINK}"    ),  ),  // ...)
  2. 2

    Implement the application(_:continue:restorationHandler:) -> Bool in your AppDelegate and call Primer.shared.application(_:continue:restorationHandler:) function.

    import PrimerSDKimport UIKit @UIApplicationMainclass AppDelegate: UIResponder, UIApplicationDelegate {   // ...   func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([UIUserActivityRestoring]?) -> Void) -> Bool {    return Primer.shared.application(application, continue: userActivity, restorationHandler: restorationHandler)  }}
  3. 3

    Implement the application(_:open:options:) -> Bool in your AppDelegate and call Primer.shared.application(_:continue:restorationHandler:) function.

    import PrimerSDKimport UIKit @UIApplicationMainclass AppDelegate: UIResponder, UIApplicationDelegate {   // ...   func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]) -> Bool {    return Primer.shared.application(app, open: url, options: options)  }}

Execute 3D Secure

Universal Checkout drop-in and headless automatically render the 3DS challenge when required by your workflow.

If your application is not installed from a trusted source (e.g. a debug version, not installed from the store, or used on an simulator), try to set PrimerDebugOptions.is3DSSanityCheckEnabled to false. Otherwise 3D Secure library initialization will fail due to security checks being performed.


is3DSSanityCheckEnabled flag should only be used in development mode, and not in production release of your app.

let settings = PrimerSettings(  // ...  debugOptions: PrimerDebugOptions(    is3DSSanityCheckEnabled: false  )  // ...)


  • If you notice a console warning "Failed to import Primer3DS" on the SDK initialization, go to Scheme settings and select Manual order. Dependencies

Test 3D Secure

Go Live

Before going live with 3D Secure, your account has to be configured for each of your processor.

To do so, please get in touch with your contact at Primer with the following information:

  • Acquirer Merchant ID
  • ARN (Acquirer reference number) - per card scheme
    For Amex - this is referred to as the Amex SE number (Service entity)
  • Merchant Category Code