Tipping a taxi driver in the UK is discretionary and never mandatory, though it is a common courtesy for good service. The most standard practice for short "street-hail" trips is to simply "round up" the fare to the nearest pound; for example, if the meter shows £8.20, telling the driver to "keep the change" from a £10 note or calling it £9 is perfectly acceptable. For longer journeys or airport transfers where the driver helps with heavy luggage, a tip of 10% is a sensible benchmark if you are pleased with the ride. In 2026, all London Black Cabs must accept card payments, and the card terminal will usually prompt you with a "tip" option; you can easily select "No Tip" or "0%" without any social awkwardness if the service was just standard. Outside of London, in private-hire vehicles (like Uber or local minicabs), tipping via the app after the journey is common but remains entirely optional. The UK culture is generally built around fair wages and transparent meter pricing, so you should only feel compelled to tip if the driver goes above and beyond to help you.