Royal Mail on Wednesday unveiled the first postage stamps to feature the image of King Charles III, following his ascension to the throne last September.
The new so-called "definitive stamp" - intended for everyday use and consisting solely of the monarch's head, the stamp's value and a barcode - will go on general sale from April 4.
The image, which was approved by Charles himself, is adapted from the official effigy that appears on new UK coins after he succeeded his mother, Queen Elizabeth II.
Elizabeth died on September 8 following a record-breaking 70 years on the throne.
Retailers will continue to sell their existing stamps featuring the late queen, and be supplied with the new ones when current Royal Mail stocks have run out.
British artist Arnold Machin created an effigy of the queen for decimal coinage in the 1960s, and then designed the definitive stamps bearing her image which became an iconic symbol of the UK around the world.
The new design shows Charles facing left, as all British monarchs have done on stamps since the "Penny Black" was issued as the world's first postage stamp in 1840, under Queen Victoria.
The image of Charles is an adapted version of a portrait by British sculptor Martin Jennings, created for The Royal Mint for new UK coins, which are already in circulation.
Royal Mail chief executive Simon Thompson said British stamps are unique in not having the country of origin printed on them, "as the image of the monarch is sufficient".
