Royal Mail of Great Britain provided a wealth of information about how to obtain that nation’s special postmarks in its monthly Postmark Bulletin. Most of that information is reproduced below.
Items for reposting, individually addressed and bearing at least the 1st class postage rate should be sent to the reposting address given. To ensure prompt handling please mark the outer cover ‘Special Handstamp’ and state clearly the serial number(s) of the handstamp(s) required. On the first day of issue of new stamps items not clearly marked will receive the ‘First Day of Issue’ cancellation. The outer cover must bear normal postage and only those items bearing the postmark on or before the date of the special handstamp will be eligible for the cancellation.
Collectors who want their covers/cards returned under cover after handstamping should enclose a suitable self-addressed envelope. This need not bear additional postage stamps, the postage being already paid by the stamp affixed to the covers for postmarking.
For customers submitting covers/cards for more than one postmark, please use/provide a separate envelope for each postmark. Customers are also asked to clearly mark/identify the postmark number required. This will help Royal Mail process the covers/cards more efficiently.
The monthly listings will be organized by the separate Special Handstamp Centres and others who apply the postmarks, along with an image of the postmark and its individual serial number.
The addresses of the Special Handstamp Centres follow:
London Special Handstamp Centre
LONDON, EC1A 1BB
Northern Special Handstamp Centre
Royal Mail Tallents House
21 South Gyle Crescent
EDINBURGH EH12 9PB
Wales & The West Special Handstamp Centre
220-228 Penarth Road
CARDIFF CF11 8TA
There are also a number of permanent pictorial handstamps available from the Special Handstamp Centres as listed below: