On most routes in London you have to buy the ticket before you get on.
Exact money only, of course.
Until a couple of years ago it was 70p for a journey within or without Zone 1, 1 quid if you entered or left Zone 1. Then they had this big advertising campaign saying 'London is now a one-fare city!', as if they were making it easier for you. Except thet just made ALL journeys 1 quid.
And now it's a quid and 20p.

I think the lesson we can learn from this is that buses are shit.
( Mr. Tea 'ulmmm'/'mmneurgh', Mon 11 Jul 2005, 16:00, archived)

Buses in London are phenomenally shit
The tube is much more likely to get you killed quicker.

Actually I find walking is the best way to get anywhere less than 5 miles away in London.

There's always destitutes to laugh at on your way.
( Goatworrier had your mum and she was shit, Mon 11 Jul 2005, 16:03, archived)