Remarketing with Klarna Checkout

Using remarketing on abandoned carts is a good way to get more customers to complete their purchases. If customers have started to enter their contact details but then decide to cancel their purchase, the merchant can email the customer, prompting them to return to the abandoned cart.

Klarna Checkout together with abandoned cart software is an effective way of increasing sales. It allows you to pre-fill email addresses and postcodes when customers return. Klarna uses the pre-filled information to identify customers and provide a one-click buying experience.


1. Obtain customer details

With Klarna Checkout Javascript API, merchants receive notifications when a customer enters data in the Checkout form. This is done by registering a callback function that receives the customer's email address, postcode, given name, and family name. 

It’s important that the callback function is registered after Klarna Checkout in the HTML code, or after Klarna Checkout has been rendered. 

This is how the callback function is registered

window._klarnaCheckout(function(api) {
         'change': function(data) {
             // Do something

The data object contains the consumer’s email address, postcode, given name, and last name. Fields that have not been filled are sent as empty strings.

An example of a data object:

     "email": "",
     "postal_code": "N5 1AW",
     "given_name": "Klara",
     "family_name": "Joyce"

2. Filter out completed purchases

To ensure abandoned cart emails are only sent to customers that have not completed purchases, the merchant must filter out orders that have been completed. This is done by removing matching email addresses from the remarketing email list. The best place to do this is on the order confirmation page where purchases are completed.


3. Send abandoned cart email

If a customer has abandoned a cart, an email should be sent, prompting them to return to it. This is a great opportunity to offer the consumer something extra if they complete their purchase. Merchants can, for example, offer customers a discount or free shipping to encourage them to complete their purchase. A popular way of doing this is to send emails in three stages: an email to remind customers about their cart; a second email asking them to complete their purchase; and finally an email offering a discount to complete the purchase.

The link in the email that takes customers back to the web store should at least contain an identifier for the abandoned cart, as well as the customer’s email address and postcode. This is needed to load the abandoned cart and to pre-fill the Checkout with its parameters.

An example of a link:


4. Pre-fill Klarna Checkout

When the customer returns to the checkout, the merchant should load the previously abandoned cart. This can for example be done by using the cartid which was included in the link in the e-mail. The merchant should then pre-fill Klarna Checkout with the email address and the postcode provided in the link from the email. Klarna will then take care of the rest: identify the customer and pre-fill the remaining fields.

This is how Klarna Checkout can be pre-filled

$orderData['billing_address']['email'] = '';
$orderData['billing_address']['postal_code'] = '12345';
orderData.setBillingAddress(new Address() {
orderData.BillingAddress = new Address() {
    Email = "";
    PostalCode = "12345";

The customer is then just one click away from converting to a completed transaction.