No, a SmarTrip card cannot be used for more than one person on the Washington D.C. Metrorail system. Each passenger aged 5 or older is required to have their own individual SmarTrip card (or mobile fare payment) to enter and exit the gates. This is because the Metrorail system uses a "distance-based" fare structure; the card "tags in" at the start of your journey and "tags out" at the end to calculate the specific fare. If you tried to tap the card again for a second person, the system would read it as a "double-entry" error. However, on Metrobus and other regional bus systems, you can occasionally pay for multiple people if you have enough "Stored Value" on the card, but you must ask the bus driver to manually adjust the farebox before you tap. For tourists in 2026, the easiest way to manage this is for each person to add a SmarTrip card to their phone's Apple or Google Wallet.