"Mizter T" wrote

Also, like it or not, lots of people in the fringes of London in some
areas - e.g. parts of the London Borough of Bromley are a good example
- would give their address as Kent, and would furthermore identify
with Kent (and also as soft of being part of Kent), at least in a
number of ways - whilst also quite possibly identifying with London as
well. Some on the edges would likely recoil as being labelled
Londoners.

There is also a good practical reason for including the unnecessary county
in a postal address. Letters addressed to
CHISLEHURST
BR7 5xx
have not infrequently arrived late with a spurious Bristol postmark. This
does't seem to happen when they are addressed
CHISLEHURST Kent
BR7 5xx

There are also cases where two post towns in different parts of the country
share a name (Ashford, Richmond, etc). While the correct postcode does
differentiate, inclusion of the county name does reduce the risk of
misrouting.

Coming back on topic, National Rail, and BR before it, have over the years
identified the Ashford station between Feltham and Staines as Ashford
(Surrey) or Ashford (Middlesex), apparently switching backwards and forwards
between the two every few years. On the same line, St Margarets has switched
between (Middlesex) and (Greater London), while Rainham (Essex) seems to
have remained as such, although it is in Greater London,

Peter