Using your credit card at the checkout is set to get a lot more complicated

A settlement between Visa, Mastercard and U.S. merchants announced this week could usher in a new era of tiered pricing at the register, giving businesses more power to charge fees depending on the credit card you use. The agreement comes after a two-decade antitrust battle over interchange fees, the charges banks collect from merchants every time a customer pays with plastic.

The settlement still needs court approval, and is likely to be contested by some merchant groups, which have disagreed over the fees and other terms in the past. A deal last year fell apart after lawyers for some merchants objected.

Here’s what else to know:

Card acceptance

Merchants have always had the right to refuse to do business with a payment network entirely. Costco, for example, only accepts Visa credit cards in stores. But current network rules say that if a store accepts one Visa credit card, it has to accept all Visa credit cards.

The settlement could change that practice by allowing merchants to pick and choose which categories of cards to accept within a network. Analysts say the groupings are broad enough that merchants are unlikely to start refusing any one of the categories, including those that offer rewards. The categories would lump in midmarket cards with more premium cards, meaning they would get blocked together, TD Cowen analysts wrote in a note.

The settlement doesn’t affect debit cards.

Surcharges

A more likely outcome is that people will start to see more fees, according to analysts. Some merchants already tack on small fees when customers pay with a credit card instead of cash, but those tend to apply broadly across credit cards.

The settlement would go a step further, allowing different surcharges depending on the category the card falls into. A basic, no-frills credit card, for instance, might come with a surcharge of 2.5% of the transaction amount, versus 3% for a rewards card.

The settlement would require banks to add clear visual markers to cards to help consumers and merchants determine what category a card falls into, but that could take years to update, analysts said.

For merchants, adding a surcharge would help offset their costs, but it also risks alienating customers. A recent survey commissioned by TD Cowen found that roughly two-thirds of consumers would switch payment methods if faced with a 3% to 4% surcharge.

“People have gotten accustomed to being able to pay for the things they buy without really thinking too hard about which card to use," said Sara Rathner, credit card analyst at personal finance site NerdWallet.

Rewards

The settlement also requires an average 0.1 percentage-point reduction in interchange fees phased in over five years.

The banking industry has long argued that limiting interchange fees would threaten rewards for consumers. Analysts, however, say that the reductions spelled out in the settlement aren’t enough to result in sweeping changes to card rewards or annual fees. That means the travel points, cash-back bonuses, and lounge access that have come to define rewards and premium cards are likely to stay put.

Analysts don’t expect the settlement to cause any big jumps in annual fees. For high-end, premium credit cards, such fees have already climbed sharply in recent years, helping fund richer perks. Many premium cards also now offer statement credits for specific purchases that are partly funded by merchants, further insulating issuers from small revenue shifts.

If anything, the new rules may push banks to compete even harder to keep high-spending customers loyal, because merchants will have new incentives to steer shoppers toward cheaper forms of payment.

“I can’t imagine any issuer would want to take [rewards] away if it’s really popular," Nerdwallet’s Rathner said.

Write to Imani Moise at imani.moise@wsj.com