A semipostal stamp offers the option of contributing additional money to a charity or cause when purchasing a postage stamp.
The name is fitting, therefore: As a "semipostal," only part of the price of the stamp pays for postage. The rest is donated to a designated fund.
Semipostals were first offered by one of the British Empire's colonies in what is now Australia.
In 1897, the United Kingdom was celebrating the diamond jubilee of Queen Victoria, who became queen 60 years earlier.
New South Wales issued two stamps to commemorate the jubilee. But these new semipostal stamps also served an important second purpose. A large surtax was added to the cost of the stamp, and the money collected was designated to pay for the construction of a facility in Sydney to care for tuberculosis patients.
The stamps served as a souvenir of the diamond jubilee, and as an easy way to donate toward the home for consumptives (tuberculosis patients).
The green and brown stamp was valid for 1 penny in postage, but the cost of the stamp was 1 shilling. The rose, blue and gold stamp had a 2½d postage value, but the cost of the stamp was 2sh and 6d.
The difference between the rather steep price of each stamp and its actual postage value was donated to the consumptive's home charity.
In the Scott catalogs, semipostal stamps are listed with a prefix "B," so the two stamps from New South Wales are Scott B1 and B2.
Semipostal stamps appear after the end of the regular postage stamp listings in the Scott Standard Postage Stamp Catalogue, the Scott Classic Specialized Catalogue of Stamps and Covers 1840-1940, and the Scott Specialized Catalogue of United States Stamps and Covers.
Another colony in Australia, Victoria, also issued two semipostal stamps honoring the queen in 1897, about four months after New South Wales. These stamps have the same pricing structure as those from New South Wales, and the money was also designated for a hospital fund.
Over the years, semipostal stamps became more common, particularly in certain European countries.
Germany, for example, has issued well over 1,000 semipostal stamps since its first two, in 1919, were created to collect donations for individuals wounded during the war.
Belgium has also issued more than 1,000 semipostals.
Early semipostals are often difficult to spot among regular postage stamps.
Many of Switzerland's early semipostals are inscribed only with the country name (as "Helvetia"), the postage value of the stamp, the phrase "Pro Juventute," and the year of issue.
A 10-centime semipostal issued in 1927, for example, only has the number "10" inscribed for a value, but it sold for 15c, with the additional 5c serving as a charitable donation to a fund aiding children.
Sometime around the 1920s or so, most countries issuing semipostals began marking the respective postage and charity values more clearly.
Switzerland's 1938 Pro Juventute semipostal set, for example, includes a single stamp with the value inscribed as "10+5," indicating that the stamp has a postage value of 10c, and an additional 5c cost for the charitable donation.
This number-plus-number inscription has made most modern semipostals easy to identify.
With the growing prevalence of nondenominated postage stamps, it is again becoming difficult to distinguish semipostals from ordinary postage stamps.
France began issuing semipostals in 1914, and most of the stamps show two values connected with a plus sign.
But since 2003, French semipostals have shown either one value or none at all. The 2006 stamps benefitting the Red Cross only have a small Red Cross symbol and the phrase "Lettre 20g" (Scott B711-B712). But the stamps cost E0.71 each, combining a E0.54 postage value and a E0.17 surtax.
The United States did not issue any semipostal stamps until 1998, more than a century after the first semipostals were issued in New South Wales.
There has been some resistance to semipostals among U.S. stamp collectors, who assert that most of the stamps are sold to collectors, and therefore put the collector building a new issue collection in the position of having to pay extra and support a charity to obtain the needed stamp.
The four semipostals issued so far in the United States are the 1998 Breast Cancer Research stamp (Scott B1), the 2002 Heroes of 2001 stamp (B2), the 2003 Stop Family Violence stamp (B3), and the 2011 Save Vanishing Species stamp (B4).
The Breast Cancer Research stamp is simply inscribed "First-Class" with no denomination, while the three stamps that followed have a slightly modified inscription reading "First-Class +."
These stamps have each fulfilled the then-current letter-rate postage value and included a surtax ranging from 7¢ to 14¢ per stamp.
Along with collecting the stamps themselves, many collectors also like to preserve postal history that includes mailed envelopes saved intact which show the semipostal stamps serving their postal duty.