AFTER six years in Southern California, Prince Harry and Meghan Markle are preparing to move back to the UK later this month — and it’s expected to be for an extended period.

The relocation will take in their children, Prince Archie, 7, and Princess Lilibet, 5, with the pair set to be enrolled in school in Britain. Despite the transatlantic shift, the couple are not planning to sell their $14.5 million Montecito estate.

The move is already being painted as a potential fresh headache inside the royal family — particularly for Prince William. Royal reporter Tom Sykes said the long-running rift between the brothers means Harry’s return could create a new run of awkward moments, from whether King Charles might invite Harry back for Christmas to whether Harry will want to attend key national events such as Remembrance Day commemorations.

On the King’s position, Sykes said he believes there’s “no way” Charles didn’t know the move was coming. A source said Charles learned of Harry and Meghan’s intentions on Sunday.

The shift also reopens the security question. Last year, Harry said he couldn’t imagine bringing Meghan and the children back to the UK after the Royal and VIP Executive Committee (RAVEC) ruled the family was not entitled to extra security during visits. With the upcoming move, RAVEC will reassess the situation.

The move follows Harry’s reunion with his father in July, as Charles continues to live with cancer. Last year, Harry told the BBC: “I don’t know how much longer my father has.”

Sources said the couple’s decision was driven by a desire to be closer to Charles and to give Archie and Lilibet the chance to build family relationships. Sykes also suggested the couple’s life in America hasn’t played out as hoped, pointing to possible financial motivations — and arguing that if a major new deal was on the table, they wouldn’t be “rushing home.”

Meghan’s time in California has included her lifestyle brand, As Ever, and her Netflix series “With Love, Meghan,” which ran for two seasons.