Klarna Group Plc is partnering with Walmart Inc.-backed OnePay to offer buy-now-pay-later to US shoppers, replacing Affirm as the retail giant’s fast credit option.

Klarna will be available via finance app OnePay at online and physical checkouts of Walmart, according to a statement on Monday.

“This is a game changer,” said Klarna’s chief executive officer Sebastian Siemiatkowski. The deal gives Klarna access to the big box retailer’s millions of customers and a new avenue of expansion in the US, already one of its fastest-growing markets.

Affirm Holdings Inc. is currently a Walmart partner, but Klarna will become the exclusive option for installment loans once the integration is rolled out this year. Shares in Affirm dropped as much as 13.46% on Monday.

Affirm said in a statement that its integrated program with Walmart represented about 5% of its gross merchandise volume and approximately 2% of its adjusted operating income in the six months through December, and its products are also available via direct-to-consumer offerings such as the Affirm Card.

The tie-up comes days after Klarna filed publicly for a US initial public offering in what could be one of the year’s biggest financial company listings. Klarna is seeking to raise at least $1 billion and is targeting a valuation of more than $15 billion in the listing, Bloomberg News reported.

The Stockholm-founded digital payments company’s revenue climbed 24% last year. Klarna had net income of $21 million on revenue of $2.81 billion for 2024, according to its filing Friday with the US Securities and Exchange Commission. The company had 93 million customers globally across more than 675,000 by the end of December, according to the filing.