Mrs Payne has raised just over £390,000 in the last two months, with her money going to the NHS, Highlands Hospice and RNLI. She has 30 flights of stairs left in her challenge. Charles wrote: “My wife and I just wanted to add to what I suspect is a very large number of messages of support by saying how inspiring it has been to witness the huge success of your fundraising efforts.
“These past few months have seen our country face immense challenges. Many people are grieving the tragic loss of their loved ones.
“The marvellous community spirit, for which Scotland is so renowned, has never been so much in evidence as people across our society have gone the extra mile, have put others first and have sacrificed their own comfort for the common good.
“There could hardly be a better example of this indomitable spirit than your own magnificent efforts in raising money for vital charities. It is people like yourself who show that, for every hardship there has been a hero – or, of course, a heroine…
“So, in great admiration of your incredible efforts, my wife and I send you our warmest congratulations on your splendid achievement!”
Mrs Payne previously told PA: “I am completely overwhelmed and humbled by the generosity of everyone who has donated to this amazing cause.
“I would like to thank each and everyone for their heart-warming messages of support and generous donations, which are providing greatly appreciated encouragement as I slowly but surely make my way up the mountain.
“I am very much looking forward to enjoying a good rest at the summit, and celebrating with my family and chosen charities.”
Suilven lies in a remote part of the Highlands.
READ MORE: Princess Anne becomes first royal to resume in-person visits
“So it was a way of saying thank you from me for the extraordinary care and support they’ve given to my family.”
Sir Tom is a former British Army Officer who in the run-up to his 100th birthday on April 30, began to do laps of his garden for NHS Charities Together.
When the campaign closed, it had raised £32.79 million.
In recognition of his feat. Sir Tom was given a knighthood in May.
Sir Tom was the guest of honour by video link and opened the NHS Nightingale hospital in Harrogate.
He was given a Pride of Britain award and given the ranks of Honorary Colonel of the Army Foundation College in Harrogate.
Sir Tom was also awarded a Blue Peter gold badge and given the Freedom of Keighley and Freedom of the City of London.
His autobiography “Tomorrow Will Be A Good Day” is scheduled to be published in September.
Donate to Margaret’s stair-climbing challenge at virginmoneygiving.com