Royals King Charles and Queen Camilla Use New Portrait — First Seen Displayed in the Palace — for a Special Card Those celebrating a special birthday are in for a glamorous treat when they check the mail By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Writer and Reporter at PEOPLE. People Editorial Guidelines Published on February 24, 2023 10:13 AM Share Tweet Pin Email A glamorous new portrait of King Charles III and Queen Camilla is in the mail. During the King's meeting with President Volodymyr Zelenskyy of Ukraine at Buckingham Palace earlier this month, a previously unseen picture of King Charles, 74, and Queen Camilla, 75, was displayed on a table behind them. The image appeared to be a formal portrait of the couple taken during the first state banquet of the monarch's reign in November 2022, when Cyril Ramaphosa, president of South Africa, made his three-day state visit to the United Kingdom. Now, the portrait is being used for a special reason: to celebrate the 100th birthdays of U.K. residents! In a post shared on Twitter by Colchester Borough Homes on Feb. 24, they wrote that Catherine Ford had received a card featuring the new snap from the King and Queen Consort to celebrate her milestone birthday. In a better look at the new portrait, King Charles and Queen Camilla smile and stand close together in their formal wear, complete with Camilla wearing the Belgian Sapphire tiara, previously worn by Queen Elizabeth II. How King Charles and Queen Camilla Will Make Royal History at Their Coronation This May Twitter user SpikeArmstrong also shared photos of his grandfather's birthday card on social media, sharing a look at the message inside. "My wife and I are so pleased to know that you are celebrating your one hundredth birthday on 21st February, 2023," the message from the King said. "This brings our warmest congratulations and heartfelt good wishes on such a special occasion." King Charles and Queen Camilla. Chris Jackson/Getty The note was signed by both Charles and Camilla, both completing their signatures with an "R," standing for "Rex" (Latin for king) or "Regina" (Latin for queen), respectively. King Charles Chooses Sweet Childhood Photo with Queen Elizabeth to Thank People for Condolences King Charles and Queen Camilla sent out their first round of birthday cards from the palace shortly after Charles became monarch following the death of Queen Elizabeth in September. However, those cards featured a photo of the royal couple from the summer of 2018. Thousands of birthday cards are sent from Buckingham Palace each year to residents celebrating their 100th and 105th birthdays...and every year thereafter. Couples celebrating their 60th, 65th and 70th wedding anniversaries receive a card as well. The tradition dates back to 1917 during the reign of King George V. During Queen Elizabeth's reign, approximately 1.3 million cards were sent to mark birthdays and anniversaries across the U.K., the realms and the overseas territories, per Buckingham Palace. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! King Charles and Queen Camilla. Andrew Milligan - Pool/Getty To receive a card, residents must apply online with a copy of the celebrant's birth certificate or passport. Only current citizens of the U.K., countries where King Charles is head of state or U.K. overseas territories are eligible to receive messages.