Payment through PayPass will cost the same as having paid on Oyster - including the discounted rates. From 2013 that's £1.40 for a single ride. However, unlike using an Oyster Card, there are no daily limits. Cash payments will cost £2.40 from 2013.
More top news
A lamp in the tower which houses Big Ben is to be switched off for the first time in more than 70 years.
Sir Bruce entertained audiences for more than seven decades.
Work in the tower will also pause over the bank holiday weekend.