Prince William and Kate Middleton officially register Prince Louis' birth – see certificate

By: Ainhoa Barcelona

Prince Williamand Duchess Katehave officially registered the birth of their third child, Prince Louis. The Duke signed the registry at Kensington Palace overseen by a registrar from Westminster Register Office. The official document lists the baby's date and place of birth as 23 April 2018, St Mary's Hospital, Praed Street, Westminster. The newborn's full name and surname is listed as His Royal Highness Prince Louis Arthur Charles of Cambridge.

RELATED: All the photos from the Prince Louis' debut

Royal watchers were quick to note William and Kate's occupations of 'Prince' and 'Princess of the United Kingdom', respectively, while their places of birth – Paddington for the Duke and Reading for the Duchess – were also documented. The baby's 'usual address' is the family's home, Kensington Palace.

While parents in the UK legally have 42 days to officially register a child's birth, William and Kate registered their son's arrival eight days after he was born. And unlike most parents, the royals did not have to wait in line at the register office. A registrar travelled to Kensington Palace where William signed the document from the comfort of his home.

Westminster City Council registrar Alison Cathcart did the honours for Prince George andPrincess Charlotte's births in 2013 and 2017. After George was born, Ms Cathcart said at the time: "It was a pleasure. Westminster City Council registered the birth of the Queen and Prince Charles and Princes William and Harry, so it's great to see that tradition continue."

William and Kate registered George 11 days after he was born. In contrast, they registered Charlotte's birth just three days after she arrived on 2 May 2015. While the Duke and Duchess announced their elder children's names just two days after the birth, the couple waited four days before revealing Louis'. William had admitted they were still "working" on a name. The statement on Friday read: "The Duke and Duchess of Cambridge are delighted to announce that they have named their son Louis Arthur Charles. The baby will be known as His Royal Highness Prince Louis of Cambridge."

Don't miss a beat with HELLO! Canada's Daily Hits newsletter, your daily dose of royal and celebrity news, fashion, weddings and more. CLICK HERE to sign up for free!