+add as contact
"I'm curious how the congestion charge works. There are a few places I'd like to visit again - I lived there for 12 years and wondered where I get access without getting a heavy fine? Also, what are the charges for a day or evening?"
Charges and how to pre or post -pay is available by Google (Google is your friend).
As for the reason for doing so covers a multiple of reasons, none of which can be fully comprehended:
(A) you've had a mad moment and want a raise your insurance premiums through a certain accident with an uninsured driver..
(B) You lost a bet with your mates and they want you to drive into London with a 1963 paper street map as guidance!
(C) The best shag you ever had was with a guy who lives in London who wants you to pick him up for a drive into the country..
(D) You love being risky and you were told about the 'poo your pants' route via Piccadilly, into the circus, up Shaftsbury Ave, over to the Embankment, into Parliament Square, go round it twice then make your way over to Tower Bridge.
....and you want to pay for this?