We’ve all been in situations where we’ve had to run to catch our flight. 

Now, it seems, we may need to run a bit faster. Or maybe not run at all. 

Effective immediately, you’ll need to check in for your flight earlier or risk losing your seat. 

One airline, United, says that if you’re traveling without checked bags, you now have to check in at least 45 minutes before flight time. 

The previous cut-off time was 30 minutes. The 45 minute rule applies to passengers with checked bags as well. 

If you miss that cut-off time, you’ll lose your seat, and that may mean not getting rebooked on the same day if other flights are packed.