**Last updated**: 24 June 2025 | [**Change log**](/products/checkout/web/changelog/) # Formatting ## 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 ```javascript (function () { var form = document.getElementById("card-form"); var clear = document.getElementById("clear"); Worldpay.checkout.init( { id: "your-checkout-id", form: "#card-form", fields: { pan: { selector: "#card-pan", placeholder: "4444333322221111" }, cvv: { selector: "#card-cvv", placeholder: "123" }, expiry: { selector: "#card-expiry", placeholder: "MM/YY" } }, enablePanFormatting: true }, function (error, checkout) { if (error) { console.error(error); return; } form.addEventListener("submit", function (event) { event.preventDefault(); checkout.generateSessionState(function (error, sessionState) { if (error) { console.error(error); return; } // session state for card details alert(sessionState); }); }); clear.addEventListener("click", function(event) { event.preventDefault(); checkout.clearForm(function() { // trigger desired behavior on cleared form console.log('Form successfully cleared'); }); }); } ); })(); ```