There’s a reason why Camilla, Duchess of Cornwall, has called her husband, Prince Charles, a workaholic.

At a briefing on Wednesday for the annual royal financial report, it was revealed that the Prince of Wales has written more than 2,400 letters a year – almost seven a day.

According to People magazine, many are written directly to members of the public. The 73-year-old reportedly receives tens of thousands of missives a year.

"Very often, when members of the public write to him, they may be surprised to see on their doormat a personal letter to them from the heir to the throne," a royal source told the outlet.

PRINCE CHARLES HAD ‘EMOTIONAL’ VISIT WITH MEGHAN MARKLE, PRINCE HARRY’S DAUGHTER LILIBET, SOURCE CLAIMS

Prince Charles

Prince Charles spends most of his time in his office writing letters. (Jeff J Mitchell/Getty Images)

"It is all about listening," the insider shared. "He says, ‘We only learn when we listen,’ and when members of the public write to him, that is a form of active listening. He really does take the thoughts and comments on board and learns from them."

According to the outlet, Charles’ youngest, son Prince Harry, once joked that his father, who is known to be at his desk until well until the night, would wake up with paper stuck to his face.

Charles has spent the past three decades trying to overcome the fallout from the messy breakdown of his marriage to Princess Diana.

It took years for many in Britain to forgive Charles, whose admitted infidelity and longtime links to Camilla torpedoed his relationship with Diana, known as "the People’s Princess" for her ability to connect with the public in a way her husband never could. The Princess of Wales, who would have turned 61 July 1, died in a Paris car crash in 1997, five years after her split from Charles. She was 36.

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

Prince Charles Princess Diana

Princess Diana would have turned 61 July 1. (Tim Graham Photo Library via Getty Images)

The public mood has softened since Charles married Camilla Parker Bowles in 2005.

Now known as the Duchess of Cornwall, Camilla, 74, has taken on roles at more than 100 charities, focusing on promoting literacy, supporting victims of domestic violence, helping the elderly and other issues. Her warmth softened Charles’ stuffy image and made him appear more relaxed, if not happier, as he cut ribbons, unveiled plaques and went about the often humdrum tasks of royal duty.

Earlier this year, Queen Elizabeth sought to bolster the couple’s position by expressing her "sincere wish" that Camilla be known as "Queen Consort" when Charles becomes king. The 96-year-old's words rejected arguments that the history of the relationship should relegate Camilla to some lower status, transforming her from homewrecker to future consort with the swipe of a pen.

Charles, meanwhile, has been ready to step in whenever required, most dramatically when he presided over the opening of Parliament and delivered the Queen’s Speech earlier this year, laying out the government’s legislative program.

PRINCE CHARLES DENIES WRONGDOING OVER BAGS-OF-CASH CLAIM INVOLVING QATARI POLITICIAN

Prince Charles Queen Elizabeth

Prince Charles, Prince of Wales, known as the Duke of Rothesay when in Scotland, and Queen Elizabeth II attending the Queen's Body Guard for Scotland Reddendo Parade in the gardens of the Palace of Holyroodhouse, Edinburgh, Scotland, June 30, 2022.  (Jane Barlow/WPA Pool/Getty Images)

"Prince Charles is the longest-serving heir we’ve ever had," Robert Hardman, author of "Queen of Our Times: The Life of Elizabeth II," said. "He’s there. He’s on standby to do whatever needs doing if the queen can’t be there. But, you know, she made an oath that she was going to reign for her life. And that’s how she views it."

Because Charles has been waiting in the wings for so long, his passions are well known.

For example, he began campaigning for environmental causes long before they were mainstream concerns. He has been accused of meddling in politics, something the monarch is barred from, by speaking up about property developments he opposed and other issues.

During a recent trip to Canada, he waded into a highly-charged issue, acknowledging the "pain and suffering" suffered by Indigenous communities that had children taken away and abused at state-sponsored residential schools.

QUEEN ELIZABETH II PHOTOG ON CAPTURING 'MOST FAMOUS WOMAN IN THE WORLD': SHE 'HUMANIZED IN FRONT OF ME'

Prince Charles Camilla

Prince Charles, Prince of Wales, and Camilla, Duchess of Cornwall, arrive at the Commonwealth Heads of Government Dinner at the Marriott Hotel June 24, 2022, in Kigali, Rwanda.  (Chris Jackson/Getty Images)

It may be the shape of things to come.

CLICK HERE TO GET THE FOX NEWS APP

Emily Nash, the royal editor of HELLO! magazine, said Charles is engaged with people all over the world, particularly on the issue of climate change.

"This is very much about working collaboratively to try and improve things for future generations," Nash said. "And that’s something that Prince Charles is absolutely passionate about."

The Associated Press contributed to this report.