Yes, a 16-25 Railcard can provide a significant discount on the London Underground (the Tube), but it requires a manual setup. In 2026, you cannot simply tap your railcard at the gate. To get the 33% discount on "Off-Peak" pay-as-you-go fares and daily caps, you must take your physical or digital Railcard and your registered Oyster card to a Tube station ticket machine or a staff member. They will "link" the railcard discount to your Oyster card. Once linked, the discount is automatically applied to all off-peak journeys. This does not work with "Contactless" bank cards or Apple/Google Pay in 2026; you must use an actual Oyster card to benefit. This is one of the best money-saving hacks for students and young professionals in London, as it also applies to the Elizabeth Line and the London Overground, potentially saving hundreds of pounds a year for those who travel outside of the morning and evening rush hours.