What if signing in with a QR code doesn't work?

Make a new code on your old phone (Make a New Code) and scan it again. Each code works once and only for 10 minutes. Check that both phones are connected to the internet. If the connection drops after you tap Allow, keep both phones on the screen: the new phone shows Try Again and also continues by itself when it's back online. If the old phone says your account wasn't sent, check its connection and tap Allow again. Both phones need WitnessWork from the App Store or Google Play: a device that can't be verified can't use your account (see "Why does WitnessWork say it can't verify this device?"). If the codes on the two phones don't match, tap Don't Allow and start over, since another phone may have scanned your code. If the new phone can't scan, check that WitnessWork may use its camera in your phone's settings. If you no longer have your old phone, use your recovery key instead: on the new phone, go to Settings → Account → Use a Recovery Key. If it still doesn't work, contact support from the Help Center; never send your recovery key.