The discount wholesaler announced its new partnership with Citigroup (C) last year, which made the company the exclusive issuer of Costco co-branded credit cards, and American Express was replaced with Visa as the retailer’s credit card network. Sunday was the last day to use the Costco TrueEarnings American Express, and Monday was the first time customers could break out their new Costco Anywhere Visa Card by Citi, Consumerist reports.

The AmEx cards have been automatically canceled, and Costco members should have already received their new Visa cards in the mail. It’s now the only credit card accepted at Costco stores, though customers will also be able to make purchases with both Visa and MasterCard debit cards.

Fortune previously reported that the new Visa card is a step up from the TrueEarnings American Express. Cash-back rewards increased to 3% on restaurant and travel purchases, and to 4% on up to $7,000 spent on gas. Technically there’s no fee for the card, though you still need to pay your $55 annual Costco membership fee.

The more generous Visa could help Costco attract new customers, helping it combat recent efforts by Sam’s Club to steal shoppers away.