The Real ID deadline is Wednesday, May 7. Travelers flying within the United States will need the compliant identification to pass through airport checkpoints, marking a significant shift in security requirements.

“If they do not have any acceptable ID, we strongly suggest they arrive to the airport 3 hours prior to their departure time,” Velez told Gizmodo. Even if you arrive early, however, there’s no guarantee you’ll be allowed to board your flight. So it’s much easier if you just have a Real ID that you can hand over to security.