Charles and Camilla will welcome those who worked on Operation London Bridge and Operation Golden Orb, inviting representatives from Government bodies, the church, police forces, the media and civil institutions.
Guests at the royal gathering on Thursday will include volunteers, musicians and support staff, alongside those involved in the behind-the-scenes planning and operational running of the historic royal occasions.
The Princess Royal and the Duchess of Edinburgh will also attend.
Queen Elizabeth II’s death in September last year set in motion the long-held London Bridge blueprint – a 12-day run of meticulous arrangements, with a lying in state, vigils and a grand state funeral, all played out on a public stage.
Charles and Camilla were crowned eight months later in May this year in a deeply religious ceremony, codenamed Operation Golden Orb, followed by a weekend of celebrations.
The Palace said: “The reception will offer an opportunity for Their Majesties and other members of the royal family to thank and recognise some of the many external organisations involved for their work and efforts during these events.”
The final farewell to the late Queen, the nation’s longest reigning monarch, was held in Westminster Abbey on September 19 2022, and was attended by prime ministers, presidents and royals from across the world.
It was the nation’s first state funeral for more than half a century, with the last one held for wartime prime minister Sir Winston Churchill in 1965.
More than 2,700 military personnel took part in the procession or lined the route to the abbey.
The Queen’s coffin was placed on a 123-year-old gun carriage towed by 98 Royal Navy sailors in a tradition dating back to the funeral of Queen Victoria, with 40 sailors marching behind to act as a brake.
A moving committal service was held later the same day at St George’s Chapel in Windsor Castle for 800 guests, with the royal family joined by members of the Queen’s household past and present and personal staff from across her private estates.
With the late Queen dying at Balmoral in Scotland, it also triggered Operation Unicorn – a host of poignant ceremonial events in Edinburgh and the practical arrangements for the return of the monarch’s coffin by RAF plane to London.
Operation Marquee covered the four days of the Queen’s lying in state, focusing on the arrangements inside Westminster Hall, including ceremonial aspects, services and vigils, while Operation Feather was the plan for managing the queues outside the lying in state, with a quarter of a million people eventually paying their respects.
And Operation Spring Tide dealt with the King’s first key trips as monarch around the UK to the home nations ahead of the funeral.
In May this year, King Charles III and Queen Camilla were crowned in Westminster Abbey on a historic day of celebration.
The event brought together around 100 heads of state, kings and queens, celebrities including pop stars Lionel Richie and Katy Perry and actresses Dame Judi Dench and Dame Emma Thompson, everyday heroes, and family and friends of the couple.
The Armed Forces staged the biggest ceremonial military operation since the late Queen’s 1953 coronation, culminating in a 4,000-strong procession of servicemen and women which wound its way through the heart of London.
Tens of thousands of people turned out to see the pomp and pageantry, with Charles and Camilla processing through the streets in the Gold State Coach.
The couple, in lavish robes and wearing their crowns, took to the palace balcony to see the crowds, joined by the Prince and Princess of Wales and their children, Prince George, Princess Charlotte and Prince Louis, and the coronation pages and Ladies in Attendance.
The late Queen’s funeral and lying in state cost the UK Government an estimated £161.7 million.