More than 500 dignitaries, including political leaders and royalty, will be among the approximately 2000 people attending the funeral of Queen Elizabeth II.
The ceremony, to be held on Monday, September 19, will be one of the biggest - and most logistically challenging - diplomatic events in decades.
The last day to RSVP is today and then officials will draw up the final guest list and organise seating by seniority.
Prime ministers, presidents and royalty from around the world are expected to descend on London.
Invitations went out over the weekend to heads of state the UK has diplomatic relations with. More than 300 Foreign Office employees have been put to work on the diplomatic side with most dignitaries asked to arrive on commercial flights and to be transported to Westminster by bus as officials asked them not to bring private cars to the event.
Most countries have received an invitation for their head of state and one guest. It is up to the country in question to decide whether to attend and if so, who the guest should be. Some world leaders will bring partners; others may choose fellow politicians.
However, the 14 nations that are Commonwealth Realms - including New Zealand - have been given more invitations - for the prime minister plus one, governor-general plus one and high commissioner, plus the chance to invite 10 more ordinary people from the country.
So who will be there?
The royals
King Charles III and his wife Camilla, Queen Consort, will lead the mourning for his mother Queen Elizabeth. His three younger siblings and their spouses will be there: Princess Anne and her husband, Sir Tim Laurence, Prince Andrew, and Prince Edward and his wife Sophie, Countess of Wessex.
Charles' sons Prince William and Prince Harry, and their wives Catherine, Princess of Wales and Meghan, Duchess of Sussex, will join the family. The Queen's other grandchildren Peter Phillips, Zara Tindall, Princess Beatrice, Princess Eugenie, Lady Louise Windsor and James, Viscount Severn, will also attend.
Other royals including the Duke of Kent, Prince and Princess Michael of Kent, Princess Alexandra and Prince Richard, Duke of Gloucester, are also expected to be there.
World leaders
In the UK, new Prime Minister Liz Truss and her opposition counterpart Sir Keir Starmer will pay their respects, as will the First Minister of Scotland, Nicola Sturgeon, and Irish premier, Michael Martin.
The White House has announced that US President Joe Biden and his wife Jill Biden, have formally accepted an invitation to attend. Former American presidents Donald Trump and Barack Obama will not be there, the White House has confirmed.
Leaders of the Commonwealth including Canadian Prime Minister Justin Trudeau, Australian Prime Minister Anthony Albanese and New Zealand Prime Minister Jacinda Ardern have confirmed their attendance.
Ardern is leading a delegation that will include Governor General Cindy Kiro and their acting High Commissioner Shannon Austin and their respective spouses. Māori King Kiingi Tūheitia and Ngāi Tahu kaumātua Sir Tipene O'Regan will also be part of the group.
New Zealand was also invited to send five senior holders of Royal Honours – one New Zealand Cross (Jacinda Amey), One Victoria Cross (Willie Apiata), and three Order of New Zealand (Sir Don McKinnon, Dame Silvia Cartwright and Dame Kiri Te Kanawa).
Invitations have been sent to all holders of the Victoria Cross, Britain's highest military honour, as well as the George Cross, which can be held by civilians.
Albanese, meanwhile, offered all 10 former British colonies in the Pacific region help to get to the funeral. Solomon Islands, Papua New Guinea, Samoa and Tuvalu have accepted Australia's help to fly representatives to the funeral and Fiji, Kiribati, Nauru, Tonga and Vanuatu could yet take up Australia's offer.
In Europe, national leaders who will be there include French president Emmanuel Macron, German president Frank-Walter Steinmeier, Italian president Sergio Mattarella and Finland's Sauli Niinisto.
European Commission President, Ursula von der Leyen, and European Council President, Charles Michel, will also be at the event.
Chinese President Xi Jinping has been invited but it not yet known whether he will accept the invitation. The President has been in Kazakhstan and Uzbekistan this week on his first international trip since the start of the Covid-19 pandemic.
Japanese Emperor Naruhito and Empress Masako will travel to Britain for the funeral, in a move that is unusual as traditionally, a Japanese emperor stays away from funerals because of a Shinto religious belief that considers death impure.
South Korean President Yoon Suk-Yeol will be there, his office has confirmed, while North Korean leader Kim Jong Un has not been invited.
Bangladeshi Prime Minister Sheikh Hasina and Sri Lankan President Ranil Wickremesinghe have also reportedly accepted invitations, while India will be represented by President Droupadi Murmu.
Brazilian President Jair Bolsonaro will be at the funeral, and Turkish President Recep Tayyip Erdogan is likely to be too.
It is unclear if Mohammed bin Salman, the Crown Prince of Saudi Arabia, will attend, but the invitation has been received.
Members of royal families from across Europe will also be in attendance at the funeral, with many related to the late Queen Elizabeth by blood.
Spain's King Felipe and Queen Letizia will be there and former king and queen Juan Carlos and Sofía have been invited.
King Willem-Alexander and Queen Maxima of the Netherlands, King Philippe and Queen Mathilde of Belgium, King Harald V and Queen Sonja of Norway and Prince Albert II and Princess Charlene of Monaco have confirmed their attendance.
Members of the royal families of Sweden, Denmark and Greece will also be there.
In the past few days, it emerged that the leaders of Russia, Belarus and Myanmar - three countries that the UK has diplomatic ties with - would not be invited, meaning Russian President Vladimir Putin cannot attend.
Myanmar's government was involved in a military coup last year, and the last two countries are currently under international sanctions for their involvement in the war in Ukraine.
It has also emerged that the leaders of Syria, Venezuela and Afghanistan would not be invited.
North Korea and Nicaragua are only being offered the chance to send an ambassador.
Iran is also expected to send an ambassador to represent Supreme Leader and President Ali Khamenei.