There aren't any working Subway Surfers promo codes. That's the short version. It's a bummer, especially if you remember when the endless runner regularly handed out free coins, keys, and even new characters just for typing in a code. Those days might not be totally over, but they're definitely on pause. The game's still huge, and with a sequel now in the mix, you'd think someone would bring codes back at some point. Fingers crossed.
For the moment, though, the only rewards you can earn are the ones tied to in-game challenges. Plenty of those exist, so there's still stuff to chase if you're grinding along the tracks.
One important change: the old option to redeem codes from the main menu is gone. To claim a promo nowadays, you'll need to scan the QR code or head to the official redeem page on your phone. Once you're there, type the code into the box, tap CLAIM REWARD, and you'll get bounced back to the game to see if it worked.
There are a ton of expired Subway Surfers codes floating around, too. Some of them were pretty generous back in the day, offering useful rewards and even characters. It'd be nice if a few of those made a comeback, but for now they don't work. So keep an eye out for updates, because if any new codes drop, that's where they'll show up.