Costco warehouses accept exactly one type of credit card: Visa. Not American Express. Not Mastercard. Not Discover. Visa only — a contractual arrangement that has been in place since 2016 and that makes the Costco Anywhere Visa Card by Citi the only co-branded credit card option for members who want Costco-specific rewards while shopping at the warehouse. The card has no annual fee of its own — the requirement is an active Costco membership, which members already pay. It doub