Kate Middleton and Prince William are sending letters after Prince Louis' birthday!  

On Thursday, royal fan @TheDuchessOfWonderland posted a picture of the thank-you note they received from Kensington Palace after sending a message for Prince Louis' 5th birthday on April 23. 

The front of the card, sent on the Prince and Princess of Wales' behalf, featured an adorable photo of their youngest son — one of his official birthday portraits! Louis smiled in a blue Fair Isle sweater with a checked shirt in the snap, which was released with another image of him being pushed in a wheelbarrow by mom Kate.

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"Thank you for the very thoughtful message which you sent for Prince Louis' fifth birthday," the flip side of the card on Kensington Palace letterhead read. "Prince Louis had a fantastic day, and your message was greatly appreciated by The Prince and Princess who send you their very best wishes." 

In a break from tradition, Princess Kate did not get behind the camera for Louis' birthday portraits this year. The Princess of Wales, who has previously described herself as an "enthusiastic amateur photographer," regularly takes photos of her three children issued for their birthdays. Shaking up past precedent, Louis' latest birthday pictures were taken by photographer Millie Pilkington.

Prince Harry and Meghan Markle also recently sent a special thank-you to a bike shop near their California home that surprised Prince Archie with a new bicycle on his 4th birthday. 

As much of the world watched the coronation of King Charles on May 6, the owners of Mad Dogs & Englishmen Bike Shop in Montecito thought of the little prince. Shop owner Jennifer Blevins tells PEOPLE that her British partner and shop co-owner, Martin, spontaneously decided to send Archie some new wheels. 

"He went and he got one of our little specialized kids' bikes — they're really nice little bikes — and he's like, 'This one's perfect, it's got training wheels,' " Blevins says. "And so he went and got some birthday balloons, and he got some flowers for Meghan and a birthday card, and he said, 'Okay, I'm gonna bike over and take it to their house.' "

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Upon arrival, Blevins said security asked Martin if he was invited by the Duke and Duchess of Sussex.

"He said, 'I'm just a British business in town that wanted to give Archie a gift,' " she laughs.

Martin got the green light to leave the gift, and Mad Dogs & Englishmen team was surprised with a thoughtful thank you on June 7. 

"On behalf of Prince Harry and Meghan, The Duke and Duchess of Sussex, please accept their sincere thanks for the thoughtful gift you sent to Prince Archie for his fourth birthday. The bike has brought much joy, and is most appreciated by the family. They asked that I convey their gratitude at the lovely surprise," a letter from Prince Harry and Meghan's office posted to the bike shop's Instagram read. 

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Blevins tells PEOPLE she and Martin hope that Princess Lilibet, 2, can also use it one day!

"His little sister Lili can enjoy it too as she grows — it'll be one that both of them like," she says. 

Prince Harry, 38, traveled to the U.K. for the coronation of King Charles and Queen Camilla on May 6, while Meghan stayed back with their two young children on Archie's birthday.

The Duke and Duchess of Sussex will not attend the next big royal event, Trooping the Colour on Saturday. Harry and Meghan were not invited to the annual public celebration of the British monarch's birthday, held for the first time in King Charles' honor.