Some bands are notorious for ignoring the curfew. U2, for instance, once played until 11:30 PM and paid a £10,000 fine. That’s like ordering a pizza and being charged an extra tenner for late delivery—annoying but affordable for a band worth hundreds of millions.
Also, special events like charity shows or festivals held at the O2 might run later. And if you’re seeing a gig that’s part of a series like “The O2 Presents: All Night Weirdness,” check the website. But 90% of the time, the answer is: before midnight, you’ll be outside, wondering where you parked.
So, in summary: plan to leave your seat around 10:50 PM, skip the last encore if you value your sleep, and for the love of all that is holy, don’t buy a hot dog from the guy outside the tube station. The O2 is a magical place, but it runs on a tight schedule and a tolerance for overpriced nachos. Now go enjoy the music—and set an alarm on your phone for 10:45 PM.