Postage stamp prepaying. From when the first postage stamps were used, postmarks were applied to prevent the stamps being used again. The first stamp, the "Penny black", became available for purchase 1 May 1840, to be valid as of 6 May 1840. Two days later, 8 May 1840, the Two penny blue was introduced. The Penny black was sufficient for a letter less than half an ounce to be sent anywhere within the UK. Both stamps included an engraving of the young Queen Victoria, without perforations, as the first stamps were separated from their sheets by cutting them with scissors. The first
Postage stamp demonetization 1901 (this agency would be disaggregated on 1 July 1975 in part into the Australian Postal Commission trading as Australia Post). All then-current colony stamps which continued on sale became de facto Commonwealth stamps. Some of these stamps continued to be used for some time following the introduction in 1913 of the Commonwealth's uniform postage stamp series. These stamps continued to be valid for postage until 14 February 1966 when the introduction of decimal currency made all stamps bearing the earlier currency invalid for use. In Hong Kong postage stamps have been demonetized only once, which happened because of the