citi-cardScreen Shot 2016-06-20 at 8.11.51 AMGood news for Visa holders: Starting today you can finally use your credit cards at Costco.

For many years, Costco shoppers could only use American Express credit cards. The long-awaited switch to Visa took effect Monday.

Issaquah-based Costco also completed the switch of its store-branded credit card from American Express to a Visa card by Citi.

Approximately 118 million people in the U.S. have at least one Visa credit card, triple the number of American Express users, according to NerdWallet.

Costco and Citi automatically switched all store credit card users to the new card without checking credit scores. New cards started going out to customers in May.

Costco will continue to accept cash, checks, debit cards, Electronic benefit transfer cards, Costco Cash cards and other forms of payment.

Benefits of the new card include 4 percent cash back on the first $7,000 spent on gas per year at Costco and other gas stations, and 1 percent after that; 3 percent back on restaurants and some travel purchases; 2 percent back on all online and in-store Costco purchases; and 1 percent back on everything else.

The Citi credit card also serves as a Costco member card, so there is no need to carry two cards.

American Express stock dropped 6.4 percent after the end of its partnership with Costco was announced, and it is expected to continue to impact earnings throughout the year. Some people only had American Express cards because of the partnership with Costco, Eric Wasserstrom of Guggenheim Securities, told MarketWatch.

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