The first post box with the CIIIR cipher of the new king entered service at 8.00am today (12th July).

The box was unveiled on the High Street, Great Cambourne, by pupils from The Vine Inter-Church Primary School in Upper Cambourne and HM Lord-Lieutenant of Cambridgeshire, Mrs Julie Spence OBE CStJ QPM.

The pupils posted the first letters in the box, using Special Stamps that celebrated His Majesty’s Coronation. As a school project, each of the children was asked to write a letter to The King about the school’s Forest School, which will be opening in September 2024. The pupils also expressed their interest in the environment and asked King Charles his advice on moving towards a more sustainable future.

The post box carries a special plaque on the back, recording its historic role. In the 172-year history of letter boxes, a change in cipher to that of a new monarch has previously only happened five times; this is the sixth occasion. Boxes in Scotland will continue to bear just a representation of the St. Andrew’s crown not the CIIIR cipher.

At the same time, Royal Mail has announced an update in its cruciform logo; in England and Wales a representation of the St Edward’s crown has surmounted the royal cipher of EIIR for Elizabeth the second, this will be replaced by a representation of the Tudor crown over CIIIR.