Want to follow suit? Here’s our guide to throwing a party, Mossy-style.
PICK A THEME
Kate’s 30th was entitled ‘The Beautiful and the Damned’, her 40th took its cue from Glastonbury and her wedding channeled rock ‘n roll Great Gatsby.
NAIL THE VENUE
Claridges, The Groucho Club, The Dorchester and Sam Taylor-Wood's Marylebone house have all played host to Moss extravaganzas. Don't want to go out? Throw a couple of yurts up in your back garden and create a mini festival instead.
DON’T SETTLE FOR JUST ONE PARTY
For Kate’s 40th she celebrated with a lunch, followed by a dinner, followed by a three day party in the Cotswolds. As you do.
MAKE SURE THE MUSIC’S GOOD
Bryan Ferry, Beth Ditto, Shirley Bassey, Pete Doherty, Soul II Soul and Massive Attack have all played at Kate’s parties over the years. Note: it does help if most of these are your friends.
GO BIG OR GO HOME
On Kate’s 34th birthday, she planned to party for 34 hours. She apparently retired after 18 – which is still pretty impressive, if you ask us.
GET YOUR OUTFIT RIGHT
The sequinned blue dress Kate wore when she turned 30 is one of her most memorable outfits. And who could forget the star-covered Chanel jumpsuit she wore for her 34th?
OR GET SOMEONE GREAT TO THROW YOU A SURPRISE PARTY
Don't want to worry about the logistics? Let somebody else take control. For Kate’s 21st birthday, Johnny Depp threw her a surprise party at The Viper Room in LA and enlisted Gloria Gaynor to sing Happy Birthday to her. Top that, we say.