In message , Andrew P Smith
writes
To confuse things further there are a number of train operating
companies in Britain and more than one may serve Leatherhead station -
make sure you travel with the right company or your ticket may not be
valid.

This only matters (a) for the part from Leatherhead to the Zone 6
boundary if he's getting a travelcard and (b) when the OP buys a "Train
Company X only" ticket.

It seems all the London-bound trains are operated by South Central,
anyway.
--
Roland Perry