Upon his arrival at Buckingham Palace, the US President and his wife Melania Trump will be greeted by the Queen and receive a ceremonial welcome. Mr Trump will also be invited to inspect a guard of honour with the Prince of Wales.
On the first evening, the Queen will host a state banquet at Buckingham Palace for the president and first lady, which will also be attended by other senior members of the Royal Family.
During his trip to the UK in July 2018, Mr Trump was invited to tea with the Queen at Windsor, where he was deemed to have breached royal protocol several times.
With more eyes than ever on him for the three-day official state visit, Mr Trump might want to be aware of these etiquette rules to avoid more slip-ups.
Don’t offer your hand until the Queen does
The Royal Family’s website says “there are no obligatory codes of behaviour when meeting The Queen” but many people like to observe the traditional forms - a bow for men and a curtsy for women.
Mr and Mrs Trump were criticised for failing to display the traditional greeting when they met with the Queen last year, but it isn’t mandatory to bow or curtsy.
However, when it comes to handshakes, Mr Trump should wait for the Queen to offer her hand first.
Physical contact with Her Majesty is also strictly off-limits.
Former US First Lady Michelle Obama raised eyebrows when she put her arm around the Queen during a visit to the UK in 2009. Mrs Obama has since revealed that the pair bonded over their painful shoes.
Don’t walk in front of the Queen
During his meeting with the Queen in Windsor last year, Mr Trump was criticised for walking in front of the monarch.
He was invited to inspect the guard of honour and marched on ahead of her, before coming to an abrupt stop, forcing Her Majesty to walk round him.
The Queen usually leads the way and guests are expected to keep the same pace as her. Even her husband the Duke of Edinburgh has always walked a few steps behind her.
Address the Queen as ‘Your Majesty’
The Royal Family’s website states: “On presentation to the Queen, the correct formal address is 'Your Majesty' and subsequently 'Ma'am,' pronounced with a short 'a,' as in 'jam'.”
President Trump and his team have seemingly already broken this rule ahead of their visit.
A statement from the White House referred to the Queen as “Her Royal Majesty,” instead of “Her Majesty.”
Wait your turn at the state banquet
The Queen will take turns to speak to her guests at the state banquet. If you are seated to her right, you are the guest of honour and can expect to be engaged in conversation during the first course.
If you’re on her left, you should wait for the second course to be given the opportunity to speak to Her Majesty.
British Formula 1 racing car driver Lewis Hamilton made that faux pas during a lunch with the Queen in around 2010.
He revealed on the Graham Norton Show in 2015: “I got invited to a lunch and was sitting next to The Queen.
“I was excited and started to talk to her but she said, pointing to my left, ‘No, you speak that way first and I’ll speak this way and then I’ll come back to you.”
Stop eating when the Queen does
When President Trump is at the State Banquet, he should keep an eye on whether the Queen has put down her knife and fork.
That’s because when her Her Majesty has finished her dinner, her guests should stop eating.
She says: “It’s generally recognised that again when your host stops eating, that you should stop eating.”
Ms Messervy added: “The Queen is not a fast eater and she’s also very aware of the fact that the adage is there and so I think again, which comes back down to good manners, she’ll be keeping an eye out to make sure.
“And if someone was a particularly slow eater, I’m quite sure that she would pace herself.”