It’s officially out with the old and in with the new at Costco today, as the company closes the book on its 16-year relationship with American Express in exchange for its new deal with Citi Visa. 

That means if you’re planning to head to Costco today, you better double-check that you’ve got something other than an American Express card in your wallet before hitting the checkout lane.

The switch also means that Visa is now the only credit card accepted at Costco checkout lanes. However, shoppers can still use a Visa or MasterCard-backed debit card for purchases.

By now Costco members who previously had a store-branded AmEx card should have received their new Costco Visa Anywhere card.

The big changes for Costco began on Sunday, which marked the last day that Costco’s TrueEarnings American Express. Starting today, those cards will no longer work at the retailer.

Costco first announced the big switch in February 2015. Months later it was revealed that Visa/Citi would become the official credit card of the retailer.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.