Free Resources

Great Britain Post Office Numbers – http://www.gbps.org.uk/information/po-numbers/index.php

This resource is provided by the Great Britain Philatelic Society

In the listings here, the offices are listed in numeric order, together with the county, and in the England and Wales list the approximate date that the office was allocated that number (as taken from various Post Office listings). If more than one office is listed (other than sub-offices of the same head office), it means that the number was reallocated. If a range of dates is listed, they represent the first and last official lists in which the allocation of the number to that office appears.

The 4-Bar Postmarks for the USPS – http://www.postmarks.org/resources/PMCC_FourBarCancelsUSPS.pdf

This resource is provided by the Postmark Collectors Club

What Is My Postmark Worth – http://www.postmarks.org/resources/Value-of-Postmarks.pdf

This resource is provided by the Postmark Collectors Club

The Postmarks of the British IslesFrom 1840 to 1876 – http://www.gbps.org.uk/information/downloads/files/postal-markings/The%20History%20of%20the%20Postmarks%20of%20the%20British%20Isles%20from%201840%20to%201876%20-%20John%20Hendy%20(1909).pdf

This resource is provided by the Great Britain Philatelic Society

Barred Numeral Cancellations of Ireland – http://www.gbps.org.uk/information/downloads/files/postal-markings/1844%20Irish%20Numerals%20Scarcity%20Ratings.pdf

This resource is provided by the Great Britain Philatelic Society

The Registration ‘Rotary Device’ – http://www.gbps.org.uk/information/downloads/files/postal-markings/The%20Registration%20Rotary%20Device%20-%20Maurice%20Buxton%20(2020).pdf

This resource is provided by the Great Britain Philatelic Society

Collecting Slogan Postmarks – 1917-1969 – http://www.gbps.org.uk/information/downloads/files/postal-markings/Vol.%201%20-%20Collecting%20Slogan%20Postmarks%20(1917-1969).pdf

This resource is provided by the Great Britain Philatelic Society