In London, the most universally accepted form of identification for international visitors is a valid passport. For domestic residents, a UK Photocard Driving Licence is the gold standard for verifying age in pubs, clubs, and for purchasing age-restricted goods. In 2026, many establishments also accept digital IDs through verified apps like Yoti or the Post Office EasyID, though these are not yet a total replacement for physical documents. If you are using public transport, you don't need a photo ID; an Oyster card or a contactless bank card (including Apple Pay or Google Pay) is sufficient. However, if you are using a National Rail Railcard (like the 16-25 or Senior Railcard) to get a discount on your fare, you must carry the Railcard itself (digital or physical) as proof of eligibility. For entry into high-security government buildings or for certain banking transactions, a foreign national ID card (for EU/EEA citizens) is often accepted, but it is always safer to carry your passport to avoid any discrepancy with local security protocols or the Schengen-related entry stamps that UK border officers may look for.