Travelers flying within the US starting Wednesday must use a state-issued ID that is “REAL ID compliant” or be subject to further screening. Things seemed to be operating relatively smoothly at a sampling of US airports Wednesday morning.

U.S. travelers flying domestically are required to show a Real ID at airport checkpoints. The May 7 deadline for Americans to switch to the federally compliant identification comes after more than 20 years of being delayed.

SAN FRANCISCO (AP) — Most airports around the United States operated smoothly as new REAL ID requirements took effect Wednesday because travelers without the updated document were still allowed to move through security easily.