Earlier this month, Moore began his fundraising mission for charities that help frontline National Health Service staff battling the COVID-19 crisis by completing laps of his garden with the help of a walking frame, initially setting out to raise just STG1000 ($A1900).

As he celebrated his centenary on Thursday, the amount he raised topped STG30 million, the Guinness World Record for the most money raised by an individual through a walk.

He has also become the oldest person to notch up a No.1 single in Britain’s main music chart, featuring on a cover version of You’ll Never Walk Alone, with his endeavours winning the hearts and admiration of the public at home and across the world.

To celebrate his birthday, Moore was appointed the first Honorary Colonel of the Army Foundation College, based near the town where he grew up, a position that came with the approval of Queen Elizabeth, the Defence Ministry said.

He has also been re-presented with his World War II Defence Medal, which he had lost.

World War II aircraft carried out a fly-past above “Colonel” Moore’s home in Bedfordshire, central England, early on Thursday, with a second flyover by modern Royal Air Force helicopters due later.

Moore, who said he was still “Captain Tom”, said he was honoured by his promotion and all the kind messages he had received.

“If people choose to call me colonel, well thank you very much,” he told BBC TV with a chuckle.

Since Monday, Britain’s Royal Mail has added a special postmark to all stamped post with a congratulatory message to Moore, while more than 125,000 birthday cards have been sent to him by well-wishers, so many a nearby school has had to open and display them.

His exploits earlier this month have been heralded by politicians and royalty alike. Prime Minister Boris Johnson, who returned to work on Monday after recovering from COVID-19 himself, recorded a special message for Moore.

“I know I speak for the whole country when I say we wish you a very happy 100th birthday. Your heroic efforts have lifted the spirits of an entire nation,” Johnson said.

He said Moore, who served in South-East Asia during the war, was a “point of light in all our lives”.

The royal family have also sent messages of congratulations, including a card from the queen.

“I was most interested to hear of your recent fundraising efforts for NHS Charities Together at this difficult time,” said the 93-year-old monarch, who traditionally writes to centenarians on their birthday.

“I send my congratulations and best wishes to you on such a special occasion.”