Below are links to some useful philatelic related sites:
The Association of British Philatelic Societies (ABPS) is the national organisation catering for the needs of collectors through the Federations and local societies and those interested in philately.
MAPF - Mid Anglia Philatelic Federation of Philatelic Societies - as above but for the Mid Anglia Region.
http://www.stampfairsdiary.co.uk for a comprehensive list of fairs and events around the country.
The Great Britain Philatelic Society since it was founded in 1955 has grown steadily, and now has more than 700 members in the UK and abroad. The Society deals with all aspects of GB philately, and has contributed much to the field. It is a "must join" society for any GB collector.
The Royal Philatelic Society, London or simply "The Royal" is the oldest philatelic society in the world having been formed in 1869 (as The Philatelic Society, London, and gaining "Royal" patronage in 1906). The society has some 2000 members with roughly 900 of these in the UK. The society deals with philately from all countries and periods, has an extensive library, archive of philatelic records and material and is home to the RPSL Expert Committee.
Association of Essex Philatelic Societies is an umbrella for a number of Societies in and around Essex, including Suffolk, Hertfordshire and North London. The AEPS is a philatelic federation, a society for societies, providing the increasingly important bridge between local and national levels. The AEPS currently supports societies in Essex, East London, South-East Hertfordshire and Southern Suffolk. Just as individual collectors benefit by belonging to a local society, so individual societies are strengthened by being members of an association.
British Postmark Society
https://www.britishpostmarksociety.org.uk/
List of post offices by Ken Smith
UK Post Offices by County. Lists of Post Office branches with dates of opening, change of status and/or closure for each county in the UK
Postal Rates
https://gbps.org.uk/information/rates/ GBPS
Post Office Numbers
https://gbps.org.uk/information/po-numbers/ GBPS
Mobile Post Offices
The British Postmark Society
https://www.britishpostmarksociety.org.uk/mobile-post-offices
Special Event Postmarks
published by the British Postmark Society
Volume 1 (1851-1962) by George R Pearson – Fourth Edition, compiled by Colin Peachey and John Swanborough, published 1991. Includes supplements published in 2006 and 2016.
Volume 2 (1963-1983) compiled by Alan Finch and Colin Peachey, published 1996
Volume 3 (1984-1993) compiled by Alan Finch and Colin Peachey, published 1994
Volume 4 (1994-2003) compiled by Alan Finch and Colin Peachey, published 2004
Volume 5 (2004-2013) compiled by Alan Finch and Colin Peachey, published 2014
First Day of Issue postmarks
published by the British Postmark Society
1963 to 1983
Twenty Years of First Day Postmarks by Brian Pask & Colin Peachey
Machine Cancellations:
Krags - Machine Postmarks of Great Britain & Ireland (2nd edition, July 2022) by Paul T Carter. Published by the British Postmark Society
Universals -Mini-website of the British Postmark Society - contains lists of all the Universal Stamp Cancelling Machine dies recorded
by Paul Carter
Universal Machine Postmarks of Great Britain & Northern Ireland
Slogan Postmarks - published by the British Postmark Society
Volume 1 – Collecting Slogan Postmarks (1917-1969)
Volume 2 – Slogan Postmarks of the Seventies (1970-79)
Volume 3 – Slogan Postmarks of the Eighties (1980-89)
Volume 4 – Slogan Postmarks of the Nineties, Part 1 (1990-94)
Volume 5 – Slogan Postmarks of the Nineties, Part 2 (1995-99)
'Slogan Postmarks of the UK - 2000-2012'
"Slogan Postmarks of the UK - 2013-2020"
Slogan Postmarks of the UK - 2021
Detailed Listing of all the localities in which multi-town slogans were used
In-Depth UK Slogan Postmark Listings, 1917-1959 (in progress, contributions welcome)
PRIMARY SOURCES:
British Postal Guides / Post Office Guides
https://gbps.org.uk/information/sources/po-guides.php GBPS
General Postal Directories and Guides
https://gbps.org.uk/information/downloads/general-directories.php GBPS
including list of links to provincial directories including for East of England counties.
Post Office Circulars. Extracts 1913 – 1965
Available at International Postal Museum Charity Archive. The Royal Philatelic Society London
https://www.rpsl.org.uk/Quick-Links/IPM
Postal Treaties GBPS
Post Office Leaflets GBPS
PMG's Reports GBPS
Staff Handbooks GBPS
Miscellaneous Texts GBPS
Legislation
Acts of Parliament GBPS
Treasury Warrants GBPS
Post Office Warrants GBPS
Post Office Schemes GBPS
Appointments Register for Deputy Postmasters 1831-1956
https://gbps.org.uk/information/po-appointments/ GBPS
On Ancestry available by subscription or through some public libraries
UK, Postal Service Appointment Books, 1737-1969
The GBPS website has various other items which may contain relevant information
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