To settle the do’s and don’ts of making, changing, and canceling reservations, we talked to a maître d’, two restaurant owners, and the CEO of Resy. Here’s their advice for navigating the rocky reservation landscape.

How late is too late to cancel a reservation?

As soon as you realize you can’t make your reservation, give the restaurant a heads-up. Ideally, if circumstances allow, it’s best practice to cancel no later than 24 hours in advance, says Philadelphia restaurateur Ellen Yin, who owns acclaimed restaurants like Fork and High Street Philly. The more notice you give, the more time a restaurant has to recalibrate—whether by tossing that reservation slot back into the ring or reassigning tables before service.

One last-minute cancellation can throw off a restaurant experience, both for staff and would-be diners. If another party is set to come in at 8:30 p.m., and you cancel at the last minute, the restaurant may have to leave your table empty until the next reservation. That makes it harder for other diners who might be eagerly waiting for a notification or a phone call that space has opened up.

“It’s like playing Tetris,” Yin says. A restaurant, ultimately, is “trying to maximize your seating without having large gaps. And when somebody changes, a block falls on top of it.” And if you cancel outside of the restaurant’s stated window for doing so, don’t be surprised if you’re charged a small fee—these fees should have been noted when you made your reservation.

Can I fight the cancellation fee? And what’s the deal with that fee anyway?

Cancellation fees have become a hot-button issue—spurring everything from that unfortunate viral interaction in Boston, to a steady stream of TikToks explaining, complaining about, and defending the fees. Tim Lacey, owner of Chicago’s Atelier—which charges a full prepaid reservation deposit of $165 per person—says that a fee is a preventative measure against cancellations and no-shows. “We’re tiny, we only have 22 seats,” Lacey says. “So last-minute cancellations affect us pretty significantly.” Because every seating at Atelier is a prepaid reservation, it’s markedly more difficult to fill a no-show table at the last minute than at a walk-in friendly or otherwise larger establishment.

Despite its cutthroat reservation queue, Libertine also doesn’t see a ton of people trying to walk in for a meal because its location doesn’t see much foot traffic. That means that if someone cancels their reservation and there isn’t time for another to grab the same time slot, there’s a chance the restaurant will be forced to leave a table vacant. “When people don’t show up, or cancel very last minute… it definitely impacts our business negatively,” Pisacane says.

That said, while you shouldn’t contest a cancellation fee just because you don’t want to pay it, many restaurants are amenable to refunding in emergencies, according to Lacey. “From illness to ‘Oh, my God, my babysitter canceled,’ we can be pretty flexible,” he says. Pisacane agrees that extenuating circumstances justify a refund. But she adds that fees are made clear upon booking for a reason, and the diner is responsible for that commitment. It’s like a concert ticket, she says: “You bought the ticket and you knew the terms going into it, so you not showing up means that we lose business.”