A semi-postal stamp is a stamp issued to raise money for a charity. Usually it has two values – the postal value (the first printed value) and the additional value for the charity. The buyer has to pay the combined amount.
The first semi postal stamp was issued by New South Wales (NSW) in 1897 and the surcharge went to fight tuberculosis. It was issued to mark the diamond jubilee (60 years on the throne) of Queen Victoria and it was inscribed "Consumptives Home". The denomination is in pennies and sold for shillings.
Many countries issued semi-postal stamps during war periods, disaster times and other situations. Just prior to World War I, semi-postal stamps began to be issued by European countries, and have remained quite prevalent in Europe even today. One among them is Germany, especially during the Third Reich. During World War II philately was very popular in Germany. The Nazis used this wisely to raise money for the war and for the party. Even though they were sold at high premium rates, the collectors were willing to pay these high premiums.
The USPS has issued its first semi-postal stamp only in 1998 to raise fund for the Breast cancer research and USPS semi-postal stamps are non denominated one.
India issued a semi-postal stamp for refugee relief in 1971.
The semi postal stamps surcharge is usually less than the half the value of the postal value. One of the costliest semi postal stamp is from Falkland islands in which the surcharge and the face values are same ( 1 Pound ).
Below set of semi-postal stamps were issued on 10th April 1980, as part of Aviation History (II) series by Germany to raise money for a Youth Hostel.