OLD Routemaster buses in London

[transmanche]

Nope, passengers with paper tickets need to use the front door:

Taken from here.

Confusing isn't it!

Indeed it is. I was going by the stickers on the door which only mention the need for cash users to board at the front door. So there's no indication at the point of boarding of any requirement for paper ticket holders to board at the front door...

(Apologies for the poor quality crop, the original (pre CPC) version is included for clarity.)