It is expected that around 600 guests will descend upon St George's Chapel tomorrow to witness Prince Harry and Meghan Markle tie the knot.
The Royals aren't exactly known for their laid back family dos though and guests will be expected to follow their strict etiquette rules - reportedly issued to all those attending the ceremony - at all times. So if you were lucky enough to land an invite to the biggest event of the social calendar, grab the nude tights, put the Champagne on hold, and follow these ten must-know etiquette rules for being a guest at Harry and Meghan's big day.
Women must wear hats throughout the ceremony
The wedding ceremony has a strict dress code and men are expected to wear '˜morning dress' including a waistcoat, jacket, and tie in black or grey, whilst women must wear a day dress with a hat. The hat must be worn at all times during the ceremony, so no removing it before the 'I dos'.
Nude tights are a must
If you flirted with the idea of going getting your tanned legs out at the Royal Wedding, think again. Female guests must have their legs covered with nude tights.
High heels are a no-go
Posh Spice raised a few eyebrows at Prince William's wedding when she decided to turn up in skyscraper Louboutins, so leave the stilettos for the evening reception and opt for a shorter, more sensible heel instead.
Open toe shoes and slingbacks won't be looked upon fondly either, and don't even think about a pair of wedges.
Arms and legs should be covered
It's meant to be a scorcher on Saturday but a strappy dress will be a considered a serious faux pas, Instead guests must have shoulders covered throughout the ceremony and dresses should be no shorter than knee length. It almost goes without saying that cleavage is a no-go as well.
Go to the toilet before you arrive
Facilities will be limited when guests get to the venue so all are advised to go before hand. After all, you don't want to run past the bride whilst making your way back from the loo.
Don't try and talk to the Queen
All guests are expected to follow Her Majesty's protocol at all times and in case there was any doubt, guests should never approach or talk to the Queen, unless she instigates the conversation first. Guests should also not leave before Her Majesty has left.
No talking to the press
The last thing the Royals want are the ins and outs of their big day splashed on the front of newspapers across the country, so keep the finer details of what you see and hear to yourself.
You might get a few likes for sharing a selfie with the Queen but don't even think about trying it. Phones will not be tolerated and selfies are especially unforgivable in the presence of the Royals.
There's no John Lewis wedding list here either, guests are asked to donate to charity instead.
No getting drunk
This is a civilised affair and guests must remain sober (until the evening celebrations that is).