Amazon.com Inc. and American Express Co. are upping the ante in their bid for small-business spending.

The two companies unveiled a new co-branded card for small businesses on Tuesday. Cardholders with an Amazon Prime membership will be able to choose between an interest-free loan for 90 days or 5 per cent back on purchases made at Amazon.com, Amazon Business, Amazon Web Services and Whole Foods Market, the companies said in a statement. The no-fee metal card will also offer 2 per cent back on purchases at U.S. restaurants and gas stations and on mobile-phone services.

“It allows you to meet the need when you want cash flow, it allows you to get a savings boost from rewards when you want it,” Samant Nagpal, global head of Amazon Business payment products, said in an interview.

Amazon has been rolling out more products for small businesses in the hopes of providing them with everything from office supplies to factory parts. Last year, it started a Prime membership program offering fast, free delivery for companies. The e-commerce giant also offers small-business loans so borrowers can add more inventory or expand their businesses with new products.

AmEx, meanwhile, has been experimenting with allowing cardholders to pay off or finance individual purchases in a new feature called “Pay It, Plan It” to encourage existing customers to borrow more. The company -- which says it’s the top card issuer for U.S. small businesses, and that its portfolio is larger than those of its five closest competitors combined -- also has been focused on improving its services for small-business borrowers.

“Working capital is a very important consideration, and one that keeps business owners up at night,” said Courtney Kelso, head of U.S. commercial card solutions at AmEx. “This puts the control and choice into their hands on a transaction-by-transaction basis.”