Affirm CEO Max Levchin. Photo credit: TechCrunch on Flickr, under Creative Commons license

Affirm, the popular ‘buy now, pay later’ service, has teamed up with e-commerce company Shopify to exclusively power the latter’s Shop Pay installments in the U.S. Under the partnership, Affirm’s ‘buy now, pay later’ financing solution will be made available to eligible Shopify merchants in the U.S. who want to offer installment payment options to their customers. Using Affirm, Shop Pay customers will be able to split their purchases into four equal, bi-weekly payments.

A partnership between Affirm and Shopify could mean big business majorly for the former. Already, Affirm works with over 6,000 merchants but Shopify has hundreds of thousands more merchants in the U.S. that represent an alluring market for Affirm. Altogether, Affirm says it reaches 5.6 million shoppers across the U.S.

Affirm as a company was founded in 2012. It’s raised more than $800 million in funding from investors including the likes of Fidelity, Founders Fund, Sound Ventures, Lightspeed Venture Partners, and Ribbit Capital. Loans made through Affirm are originated through its primary partner Cross River Bank, an FDIC-insured bank based in the state of New Jersey.