Customers are unable to use credit cards sponsored by the other three main networks — American Express, Mastercard, and Discover — at Costco warehouses due to the company's exclusive arrangement with Visa. Costco.com and the Costco app, on the other hand, accept payment by Mastercard and Discover.The following is an answer to the question, "What cards does Costco accept?"

Here are a few examples of cards that may be redeemed online or via the Costco app: Chase Freedom FlexSM Citi Card with Double Cash Cash Back Learn about it. Chrome Learn about it.

Source: https://www.accountiod.com/what-credit-cards-does-costco-accept/