What area does Kent cover?

I asked this question at a meeting a few years ago when Kent County Council was setting up Kent Savers Credit Union. Obviously the credit union covers the administrative county of Kent.  It also covers Medway which most people regard as part of Kent,  although Medway is a unitary local authority.

But what of the areas that were formerly part of Kent but have been swallowed up in London outer boroughs?  Not included I was informed.

A few years on I note that Kent Savers has moved into areas now part of London outer boroughs.

From the latest Kent savers newsletter:

Welcome to Bexley

Kent Savers has now extended our membership area to include the whole of Bexley. Bexley, Sidcup, Erith and Crayford were all part of Kent until the local government reorganisation of 1965, and we are pleased to be able to extend membership of Kent Savers to those areas.