Great Britain
Postage Dues
Mail with insufficient postage applied presented a problem for postal authorities, and Postage Due stamps were created to solve it. If an item was underpaid by 1d, it would be charged at 'double the deficiency', i.e. 2d, to be paid by the recipient. Postal authorities have nearly always viewed selling mint Postage Dues as a means of raising revenue, so often mint stamps are relatively easy to obtain, but properly used (not 'cancelled to order') can be a different matter and covers showing correct non-philatelically inspired usage are often rarities.
Latest Acquisitions Below
GB 1914 SGD1/8 Postage Due U/M o.g. set eight
Stock Code: P212004684
GB 1923 SGD18var Postage Due
Stock Code: P10108017
GB 1924 SGD18var Postage Due
Stock Code: G1454925
GB 1954 SGD40/45var Postage Due
Stock Code: G1454901
GB 1914 SGD2 Cover - First day of issue
Stock Code: P201004800
GB 1914 SGD2 Cover - First day of issue
Stock Code: P201004799
GB 1954-55 SGD40/5 Postage Due
Stock Code: P190006431
GB 1923 SGD3wi Postage Due Wmk. Sideways inverted U23 control
Stock Code: P190004579