If approved, users can pay for Amazon purchases in equal installments over three to 48 months. They are charged an annualized interest rate between 10% and 36%, based on the perceived risk of the transaction, according to Affirm Chief Revenue Officer . There are no late or hidden fees, the companies said.

"The financial industry is not great at providing credit to really small businesses," Pommen said. "They can't walk into a bank branch and get a loan until they reach a certain scale. So us being able to provide this for purchases" helps business grow and manage their cash flows, he said.

The move is a boost in a crucial relationship for Affirm, which has had to search for revenue growth after for expensive bikes Affirm first began offering installment loans to Amazon's retail customers in , launched on Amazon in Canada in 2022 and was then added to earlier this year.

Affirm, which uses its to underwrite loans for each transaction it facilitates, decided to target sole proprietors first because they make up most small businesses in the country, with 28 million registered in the U.S., according to Pommen.

"We'll see how the product performs and if it makes sense to expand it to a wider universe of businesses," he said. "Our assessment is that we can underwrite this very successfully and have the strong performance that we need."