Starting Wednesday, most U.S. travelers without a passport will be required to have a REAL ID to board domestic flights.After more than a decade of warning this day would come, the Transportation Security Administration says every flier over the age of 18 will be expected to have the security-enhanced REAL ID or an approved alternative to pass through airport security checkpoints.

(NEXSTAR) — The REAL ID enforcement deadline officially begins on Wednesday, May 7, meaning those without a compliant ID may have a more complicated time boarding flights, entering nuclear power plants and certain other federal buildings.