Functional overview

Below is detailed information on some important aspects of the functionality provided with Smart Checkout.

On this page:

Checkout language

The language that Smart Checkout is presented in is determined according to this sequence:

  1. Language specified as a query parameter during the redirect by the merchant.
  2. Language selected by the customer during a previous checkout.
  3. Language specified during the creation of the payment order by the merchant.
  4. Dominant language in the merchant country.

Google Pay support

Google Pay allows customers to make payments in your website using any credit or debit card saved to their Google Account, including those from Google Play, YouTube, Chrome, or an Android device.

Google Pay is supported on Google Chrome, Mozilla Firefox, Apple Safari, Microsoft Edge, Opera, and UCWeb UC browsers. The countries in which Google Pay can be used for e-commerce are listed by Google under Pay online or in apps .

Apple Pay support

Apple Pay provides a secure and seamless payment method, which stores payment information securely in the shopper’s Apple Pay compatible device and confirms the payment through Touch ID or Face ID authentication.

Apple lists the countries in which Apple Pay is supported on their Countries and regions that support Apple Pay page.

Save payment cards for future use

Smart Checkout offers customer-side card tokenisation. This means that the customer can save their card and reuse it, while on Smart Checkout, across merchants and countries. Customers can save cards once, and use everywhere.

The merchant is not involved in this process; in fact, you will not even be aware that your customers are using a saved card. In technical terms, this means that you will not receive any card tokens yourself; the card token will remain on the browser of the customer.


Save a card

Screenshot showing the Smart Checkout payment page. Customer is about to save their card details during payment.

Save a card

Pay with a saved card

Screenshot showing the Smart Checkout payment page. Customer is about to enter their CVV before paying with their saved card.

Pay with a saved card

Payment details validation

There are two categories of validation, Inline and On submit, as shown in the screenshot below and explained in detail following on from that:

Validation categories


This type of validation occurs instantly as the customer moves between fields, but only if text has been entered.

Field validation details:

*Quick Pay only

On submit

This type of validation occurs once the customer has clicked on the button to make the payment.

Field validation details:

Pay by instalments option

The option to pay by instalment is enabled if the following three conditions are met:

The card logo is displayed once the customer has started entering the card number. For most cards only two digits are necessary before the card is identified and the card logo is shown. Maestro and Bancontact are exceptions with three and four digits required respectively before this will occur.

Payment form auto-complete

Smart Checkout allows the customer to auto-complete the card details, if this functionality is supported by the browser, in which case the customer can select from a dropdown the desired credit card and then the form will be completed with the respective card details.

3DS challenge flow

The card issuer may choose to initiate a 3DS challenge. In such a case, the issuer requires additional customer interaction, either through biometrics, two-factor authentication, or similar methods.

Payment order expiry

If the customer is unable to make a payment because the checkout process has expired, then the customer should go back the merchant store and restart the checkout process.

Browser support and overall minimum requirements

Smart Checkout is supported by all browsers as long as they are recent versions. Internet Explorer has been discontinued by Microsoft, so Smart Checkout does not support it.