If you are traveling on a UK train in 2026 and cannot produce your Railcard (either physical or digital) when asked by a ticket inspector, your discounted ticket is technically invalid. Legally, the inspector can require you to pay the difference between the discounted fare and a full-price "Anytime" fare, or they may issue a Penalty Fare (which is often £100 plus the price of the full fare). However, National Rail policy in 2026 generally allows for one "honest mistake" per year. Most Train Operating Companies (TOCs) will allow you to claim a refund for the extra costs incurred if you can later prove you owned a valid Railcard at the time of travel. You must follow the specific appeal process outlined on the back of your Penalty Fare notice. To avoid this in 2026, it is highly recommended to use the Digital Railcard on the official app, which can be stored on multiple devices and accessed offline, ensuring you always have it as long as your phone has battery.