Up there with iconic images of London is the red double decker bus.
Most run from around 05.00 to midnight, when the night buses takeover. And a lot of night bus routes stop in Trafalgar Square.
You can sometimes buy single tickets on the bus. But, in central London, you usually have to get them from a machine at the stop.
Having said that, if you want to live like a true Londoner, the smartest way is to pay by Oyster card. Pick one up at a tube station or newsagent’s, put some money on it and you can pay-as-you-go. Not only will you save time on buying individual tickets, but you’ll save money too. You can also use the Oyster on the tube and some Overground routes.
If you plan to take a few buses and tubes in a day, it might be worth getting a travelcard (see London Underground for more info).
There are a lot of bus lines in London, so make sure you know which one to take with this route finder.