The Duke and Duchess of Sussex will not be working royals allowed to carry out official engagements now they have returned to the UK, a letter sent on behalf of King Charles spells out.
The letter is intended to clarify the status of Prince Harry and Meghan, who moved back from California with children Archie and Lilibet last month.
They will still not be able to use titles of "His and Her Royal Highness", and remain "private citizens", says the letter sent on behalf of the King by the Lord Chamberlain, a top Palace official.
It comes as Prince Harry appears to have been pictured for the first time since his return, with a photo on social media showing him at a London TV and podcast studio.
The King's letter has been sent to Prince Harry's team, government departments, military officials and Lord Lieutenants, according to Palace sources.
Lord Lieutenants, who are the monarch's local representatives, and government staff are often involved in royal visits and engagements.
This letter makes clear that any engagements carried out by the Sussexes will be in a private capacity and they will not be representing the Royal Family.
It seems to be something of a shot across the bows, making clear that any Prince Harry and Meghan visits should not be treated as royal engagements.
This comes ahead of what are likely to be public appearances by the Sussexes this autumn, as they settle in the UK and support their charities.
The couple have kept a low profile, but the first picture of Prince Harry since coming back to the UK appears to have been posted on the social media account of Tower Bridge Studios in London.
The message from the King emphasises that the position agreed in 2020 when the Sussexes left the UK - the so-called Sandringham Agreement - is still in place.
This ruled out any "half-in and half-out" status, so Harry and Meghan could not pursue their own commercial interests while continuing to be working royals.
"It is well known that in January 2020 the Duke and Duchess stepped down from undertaking representative duties on behalf of the Sovereign, and are no longer working members of the Royal Family," the letter says.
The letter sent on behalf of the King makes it clear that this remains the case.
"The charitable work of the Duke and Duchess is a personal matter for them both and undertaken in their private capacity," it adds.
The King's message says that any questions from organisations about the reception to be given to the Sussexes, "particularly where recourse to public funds may be required, should be directed to Buckingham Palace".
Prince Harry and Meghan faced an acrimonious departure from the UK in 2020, which they chronicled in their Netflix documentary.
They established their financial independence in California, including Prince Harry writing a best-selling memoir Spare and Meghan creating an online food range, As Ever.
This summer the couple made a surprise return to the UK, where their children will be going to school.
It's expected that Prince Harry will be supporting his charities, including the Invictus Games, which are due to be held in Birmingham next year.
There have been reports that Meghan is considering a return to acting.
Disputes about Prince Harry and Meghan's security in the UK remain unresolved and the letter spells out: "Any operational security issues should continue to be directed to the relevant police authorities."
Prince Harry has complained about a lack of adequate police protection in the UK, but the Palace says that has to be addressed by the Royal and VIP Executive Committee - known as Ravec - which decides security for royals and public figures.
Palace sources have suggested it was better to make the Lord Chamberlain's letter public, in a spirit of transparency, rather than risk it emerging in leaks.
Prince Harry and Meghan's representatives have been contacted for a response.
