Overprint

An overprint is an additional layer of text or graphics added to the face of a postage stamp, banknote or postal stationery after it has been printed.Post offices most often use overprints for internal administrative purposes such as accounting but they are also employed in public mail. The most well-recognized varieties are commemorative overprints which are produced for their public appeal and command significant interest in the field of philately.

The term "surcharge" in philately describes any type of overprint that alters the price of a stamp. Surcharges raise or lower the face value of existing stamps when prices have changed too quickly to produce an appropriate new issue, or simply to use up surplus stocks.

Any overprint which restates a stamp's face value in a new currency is also described as a surcharge. Some postal systems have resorted to surcharge overprints when converting to a new national monetary system, such as Sierra Leone did when the British Commonwealth converted to decimal currency in the 1960s.

Stamps have occasionally been overprinted multiple times. A famous example of repeated surcharging happened during the German hyperinflation of 1921–1923. Prices rose so fast and dramatically that postage stamps which cost five or ten pfennigs in 1920 were overprinted for sale in the values of thousands, millions, and eventually billions of marks.

Victoria, 1873: Penny stamp overprinted to new value of halfpenny.

Guatemala 1881: 1 centavo surcharge on 1/4 real

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