The Duke and Duchess of Cambridge have a team of loyal and talented staff running their popular social media accounts, sharing details of their royal duties and charity projects.
But every now and again Kate and William take over the keyboard and send personal messages themselves.
William does it more regularly than his wife, normally sending messages about sport, however today, on Kate's 40th birthday, the Duchess sent her own message.
Alongside one of the three new photos shared to mark the milestone birthday, she wrote: "Thank you for all of your very kind birthday wishes, and to Paolo and the National Portrait Gallery for these three special portraits."
To let fans know the message was from her and not her staff, she signed it off 'C'.
Kate rarely sends personal messages, however the couple took to their phones to send a tweet on Christmas Day.
They wrote: "This Christmas will be different to what so many of us had planned.
"From those who are alone or having to isolate away from loved ones, to the incredible people supporting our NHS and caring for those most in need – we are thinking of you. W & C"
Before today, the last solo tweet Kate sent was on November 12 to mark a visit to celebrate the Poppy Appeal's 100th anniversary.
She wrote: "It was a true honour to spend time with Colonel Blum and thank him for the sacrifices he made for our country. Speaking to him highlighted again to me why Remembrance is so important, and why we must pay our gratitude to those who fought and died so we could live in peace today.
"We must keep their stories alive for generations to come. And many congratulations to Emily for receiving her Centenary Remembrance Badge! C"
The Queen and Prince Charles joined people around the world in publicly wishing Kate a happy birthday today.
The monarch shared four snaps on the official royal accounts, all showing her with her grandson's wife.
Her message wrote: Wishing "The Duchess of Cambridge a very happy 40th birthday today!" She also added a red balloon emoji.
Prince Charles and Camilla also used social media to send a public message to their daughter in law, writing: "Wishing the Duchess of Cambridge a very happy 40th birthday today!"
Kate is holding off her big celebrations until later in the year, when she's expected to have a joint party with William - who hits the landmark age in June.
Traditionally, the Queen will through a bash to mark the occasions, with Windsor Castle or Sandringham among the likely venues.
Similar lavish bashes have previously been thrown to jointly celebrate significant birthdays of several members of the family at the same time.
Back in June 2000 a huge do was held at Windsor to celebrate Prince Andrew’s 40th birthday, Princess Anne’s 50th, Princess Margaret’s 70th and William’s 18th.
A source told the Mirror: “It’s very much a scaled-down occasion this year for the Duchess, who will celebrate privately with her family.
“Of course she is mindful of the current situation. She will be surrounded by loved-ones and that’s all that matters.”
