Once any Royal Family member ascends to the throne, UK passports will be printed in their name and thus they will no longer require their own travel document.
Until then, though, they face all the same border checks as every other traveller – this includes visa applications when visiting specific nations.
In 2014, for example, Prince William and his wife the Duchess of Cambridge had to apply for a passport for Prince George’s first-ever overseas trip when he was just a few months old.
Of course, Royal Family members do get to enjoy some travel perks.
source: express.co.uk