In 2026, the legal and practical limits for a London "Black Cab" (Hackney Carriage) depend on where the journey starts. Legally, under Transport for London (TfL) regulations, a driver is obliged to accept any fare for a journey of up to 12 miles (or 20 miles if starting from a Heathrow Airport taxi rank) as long as the destination is within the Greater London area and the trip doesn't exceed one hour. This is known as the "compulsory distance." However, practically speaking, there is no maximum physical limit to how far a taxi can go if the driver agrees to the fare. You could technically hire a Black Cab to drive you to Edinburgh or Paris, provided you and the driver negotiate a fixed price beforehand, as the meter is typically only mandatory for journeys within the "compulsory" zone. For these long-distance trips, drivers often charge a premium to cover the "dead mile" return journey. Always remember that while a Black Cab can go far, it is grounded peer advice to use a pre-booked private hire vehicle for long trips to save significantly on cost.