The Duke and Duchess of Sussex and their two children returned to live in Britain last month, six years after stepping down from royal duties and moving to the US during a period of estrangement and awkward relations with the British royal family.
The return was a surprise even to close family with Harry's father, the King, only being told days before the news became public.
In a letter, authorised by Charles and sent to senior British officials on Monday, it was made clear that Harry and Meghan were no longer working members of the royal family.
A spokesperson for the couple said they had only been informed shortly before it was sent out and they were surprised by what had occurred.
The letter said their status, which was originally agreed with the late Queen Elizabeth in 2020, gave the couple personal latitude "in respect of financial independence and protection of their privacy as they would wish".
"It follows that there is no change to the current status of the Duke and Duchess of Sussex... The charitable work of the Duke and Duchess is a personal matter for them both and undertaken in their private capacity," it said.
"In short, their position is akin to private citizens with commercial and charitable interests."
Since leaving for the US, the couple have continued to make the headlines as Harry accused the royals of neglect, the tabloid press of ruining his life and the UK government of failing to provide automatic police protection which would allow him to return home.
A committee which decides on what level of security he should be afforded at public expense is due to meet this week to decide what protection he should have now his family have returned to Britain.
They have also struck a number of commercial deals, most notably with streaming giant Netflix, while Meghan has launched a lifestyle brand As Ever.
with Reuters
