If you don't have a Real ID driver's license by May 7, you can use a U.S. passport or Global Entry card to board your flight. Alternatively, you'll have to prove your identity. The TSA told Travel + Leisure: “Those over 18 years old without a REAL ID-compliant credential may face delays and,

You can apply and receive a REAL ID the same day. That means if you wait at a DMV and have your paperwork in order, you can walk away with the new identification, which will be required starting May 7 to travel on domestic airline flights.

REAL ID or other eligible identification is required to board domestic flights at PHL airport, or travelers risk added wait times at TSA checkpoints.