The Association of British Counties makes a number of resources available to aid in using the historic counties, including the following:
County Border Data in KMZ and SHAPE, eBook and Data Extract
on the Gazetteer of British Place Names
Match counties to Post Towns for your address database or look-up
on the Historic Counties Postal Directory
Create embed able Web Maps with County Borders or view our map
on the Gazetteer of British Place Names
You may also like to visit the following to find out more about the historic counties:
Find out more about the counties on County-Wise
Visit Wikishire, an encyclopaedia for the counties
The Historic
Counties Trust
a Registered Charity which aims to promote public awareness of the historic counties