The official monogram of King Charles III has been revealed ahead of the end of official period of royal mourning of the death of his mother, Queen Elizabeth II.

Charles’s cypher will appear on government buildings, state documents, stamps and on some post boxes in the coming months and years.

The cypher features the King’s initial “C” intertwined with the letter “R” for Rex – Latin for king – with “III” denoting Charles III, with the crown above the letters.

The monogram is Charles’s personal property and was selected by the monarch from a series of designs prepared by the College of Arms. A Scottish version features the Scottish crown, and was approved by Lord Lyon King of Arms for use in Scotland.

It will be used by government departments and by the royal household for franking mail. The decision to replace cyphers will be at the discretion of individual organisations.

The process will be a gradual one and in some instances the cyphers of previous monarchs can still be seen on public buildings and street furniture, especially post boxes.

The College of Arms was founded in 1484 and is responsible for creating and maintaining official registers of coats of arms and pedigrees. They are members of the royal household and act under crown authority.

Royal Mail also announced four stamps that feature portraits of the Queen, to be released in her memory.

The stamps – the first set to be approved by the King – will go on general sale from 10 November and will feature images of the late monarch through the years.