The first red post box with the cypher of King Charles III has been revealed by the Royal Mail.
Julie Spence, the Lord-Lieutenant of Cambridgeshire, unveiled the post box on High Street, Great Cambourne, Cambridgeshire, with the assistance of children from the Vine Inter-Church Primary School.
The pupils posted the first letters, which were handwritten notes to the King, into the freestanding stainless steel structure.
The King has granted the Royal Mail special use of his cypher, which is his personal property.
The King's cypher consists of his initial C, with the roman numeral III and an R for Rex - Latin for King - under a Tudor Crown.
The unveiling continues the 170-year-old tradition of stamping red post boxes with a royal cypher, which dates back to the reign of Queen Victoria.
Post boxes are not replaced, therefore existing boxes will retain the cypher from the period in which they were installed.
Emma Gilthorpe, the chief executive of the Royal Mail, said: "We thank His Majesty for granting us the use of his personal cypher as we begin the next chapter in the story of the iconic Great British post box in Great Cambourne."
Although some new or replacement post boxes have been installed since Charles acceded to the throne in 2022, the cypher of Queen Elizabeth II was still used to prevent wastage.
The new cypher will not be applied to new post boxes in Scotland, as since 1955 they have been distinguished by the St Andrews crown.
The King's cypher will also be applied to the Royal Mail's fleet of vehicles, an initial roll-out of 100 trucks will take place on Friday, with a further 290 over the next six weeks.
In total, 3,636 vehicles will be updated with the King's cypher between August and October this year.
The Royal Mail has recently announced a change in its brand logo, which is known as the cruciform.
The branding used on the company's vehicle livery, buildings, website and stationery, will now feature the rounded Tudor Crown used by the King, rather than the arched St Edward's crown used by the late Queen for her cypher.
The new logo will only be applied to new or replacement signage, stationery and vehicles to avoid unnecessary costs and waste. This follows guidance from the royal household, in accordance with the King's eco-credentials.
