Catherine, Princess of Wales visits the Royal Surrey County Hospital’s Maternity Unit at the Royal Surrey County Hospital on October 5, 2022

Kate Middletoncould be your royal pen pal.

As the Princess of Wales, 42, receivescancer treatment, fans may want to send the royal a letter or card filled with well wishes.

On April 6, X user AllexmarieHoll1shareda short note they said they received after sending a card to Princess Kate following the palace’s announcement that she had undergoneabdominal surgeryin January. The fan’s royal reply on Kensington Palace stationary said, “Thank you for your kind well wishes to Her Royal Highness. The Princess of Wales. Your thoughtful gesture is very much appreciated.”

Many royal fans have been sending members of the family mail for special occasions such asbirthdays, holidays,wedding anniversariesand major events like last year’scoronation. (Prince William and Princess Kate’s team evenreportedly respondedto a young girl who invitedPrince Georgeto her birthday party!)

AllexmarieHoll1 shared they sent their latest correspondence to Princess Kate at:“HRH The Princess of WalesClarence HouseLondon SW1A 1BA United Kingdom.”

Kate Middleton the opening of Evelina London’s new children’s day surgery unit on December 05, 2023.Chris Jackson/Getty Images

Catherine, Princess Of Wales attends the opening of Evelina London’s new children’s day surgery unit

Chris Jackson/Getty Images

According to the royal family’swebsite,King Charlesis also interested in letters from the public.

The website says people can write to King Charles via:“His Majesty The KingBuckingham PalaceLondon SW1A 1AA, United Kingdom.”

King Charles, 75,recently appeared in a videoreading some of the thousands of cards and letters that he received after announcing in February that he is undergoingcancer treatment. Among them was ahumorous oversized card depicting a dogwearing a veterinary cone with the caption: “King Charles, at least you don’t have to wear a cone!” Another struck a more emotional tone with the message, “The main thing is family.”

King Charles and Queen Camilla greet well-wishers after the Easter Matins Service at St. George’s Chapel, Windsor Castle, on March 31, 2024.Hollie Adams - WPA Pool/Getty Images

King Charles III and Queen Camilla greet people after attending the Easter Matins Service at St. George’s Chapel, Windsor Castle

Hollie Adams - WPA Pool/Getty Images

Etiquette expertDebrett’sgives even more guidance around how to address several members of the royal family in writing.

The site adds that letters to King Charles andQueen Camillashould begin with “‘Sir,' ‘Madam’ or ‘May it please Your Majesty’ " opening with the line “With my humble duty” and ending with the language “‘I have the honor to remain, Sir/Madam, Your Majesty’s most humble and obedient servant,’ " with the option to swap “remain” for “be.”

King Charles III and Queen Camilla wave from the balcony of Buckingham Palace, whilst watching an RAF flypast, following their coronation at Westminster Abbey on May 6, 2023 in London, England.

Envelopes should be addressed to “His Majesty The King” or “Her Majesty The Queen,” and the styling for cards to Princess Kate andPrince Williamare similar. According to the peerage authority, envelopes containing mail for Prince William should be addressed as “The Prince of Wales, KG, KT,” shorthand for his status as aRoyal Knight Companion of the Most Noble Order of the GarterandKnight of the Most Ancient and Most Noble Order of the Thistle. The honors are the highest orders of chivalry in Britain and Scotland, respectively.

Fans from the United States should add an international stamp, available to purchase at post offices, for the mail to make its way across the pond. Then, keep an eye on your mailbox for a reply.

Queen Camilla, King Charles, Prince William and Kate Middleton pose for a photo before the Diplomatic Reception at Buckingham Palace on December 5, 2023.Chris Jackson/Getty

Queen Camilla, King Charles III, Prince William, Prince of Wales and Catherine, Princess of Wales pose for a photograph ahead of The Diplomatic Reception in the 1844 Room at Buckingham Palace on December 05, 2023 in London, England.

Chris Jackson/Getty

Buckingham Palace opened up about the increase in mail following the death ofQueen Elizabethin Sept. 2022. Prior to the record-setting monarch’s death, the palace received up to 1,000 letters each week from members of the public, but their mailboxes were flooded with 50,000 letters and messages of condolence in the weeks following the Queen’s death.

The palace said at the time that all letters are carefully read and responses would be sent as the small correspondence team processes the influx of mail.

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Queen Camilla receives well wishes for Kate Middleton at the Shrewsbury Farmers' Market on March 27, 2024.Chris Jackson/Pool/Getty

Queen Camilla receives a message of support for Catherine, Princess of Wales from well-wishers during her visit to the Farmers' Market on March 27, 2024 in Shrewsbury, England.

Chris Jackson/Pool/Getty

source: people.com