The Duke and Duchess of Sussex are planning to move back to the UK, BBC News understands.
Prince Harry and Meghan intend to relocate from the US later this month to a private, non-royal residence outside London as first reported by the Daily Telegraph, external and the Sun, external.
The couple's children, Prince Archie, seven, and Princess Lilibet, five, are enrolled to start at a British school in September.
King Charles was told of the move on Sunday. There are no current plans for either Prince Harry or Meghan to resume their roles as working Royals.
The Sussexes and their children visited the King at his Highgrove home in July this year, but it is understood the move was not discussed.
The BBC understands the King was unaware of the move before last weekend but he welcomes the opportunity to see more of the Sussex family in a private and personal capacity.
No change is expected to the official status of Prince Harry and Meghan and they will remain as private individuals.
The Prince and Princess of Wales have also been informed of their plans.
The Sussexes left the UK and stepped back from their royal duties in early 2020, before settling in California in March that year.
Family relations had been strained since, with July's visit to the King and Queen Camilla being a key development in their relationship.
The Palace described the meeting at the King's private home in Gloucestershire as a "private family occasion".
It was the first time the King had seen his grandchildren in person in more than four years.
Prince Harry and Meghan had not been in the UK together since 2022, when they attended the funeral of Queen Elizabeth II.
Security for the couple has long been a point of tension, with the duke's July visit being reconsidered because his request for police protection was rejected.
Last year, Prince Harry lost a legal challenge over the levels of security he and his family are entitled to while in the UK.
The duke had sought to overturn a decision that had downgraded his security after he stopped being a working royal and moved to the US with the duchess.
It is unclear what provisions will be made for their security once they return to the UK.
Royal expert Robert Hardman said it is likely that some of the security issues "have been resolved" but details - or who is going to foot the bill - are still unknown.
"Surprise is an understatement," he told the BBC's Radio 4 Today programme of the move, adding that the Sussexes "have always been very good at delivering surprises".
Hardman said the children being enrolled in school is significant and that it signals that they are going to be raised as "British rather than American".
After the announcement of the Sussexes' intended return, a Home Office spokesperson said decisions on the security of royals were taken by the Executive Committee for the Protection of Royalty and Public Figures (Ravec), and the UK government's protective security system was "rigorous and proportionate".
Prince Harry has previously said that worries about safety have prevented him from coming to the UK and bringing his wife and children.
During his July visit the duke promoted his Invictus Games for injured service men and women, which will be hosted in Birmingham next year.
David Wiseman, chief programmes and strategy officer at Invictus Games Foundation, told the BBC that there had been a suggestion of the move when he saw Harry in July.
"He did mention to me actually that he was missing the UK, so there was a bit of a hint that he might be coming across, but I took that as a bit of sentimentality," he told the Today programme.
He said the move was "excellent news".
"I will be really pleased to have him back in the country. Moving is stressful for anyone so I hope it all goes well and the children settle well at school," he added.
"I wonder [...] whether that made a shift in his views and he really wants to come back because he's missed his life here for the last six years," she said.
Education Secretary Lucy Powell said the government welcomed Prince Harry and Meghan moving back to the UK.
Asked whether she had been told in advance, Powell told BBC Breakfast she found out about it on social media and the news on Wednesday evening "like everybody else".
Powell said she had not received any early indication from No 10 and did not know whether the prime minister had been informed in advance.
Prince Archie and Princess Lilibet being enrolled to start school in September is a "great endorsement" of the UK's education system, she said - but acknowledged that it is unlikely that they will be enrolled at a local state school.
