On Wednesday afternoon, the late monarch’s coffin, adorned with the Imperial State Crown, will be transported on a gun carriage of The King’s Troop Royal Horse Artillery.
King Charles III, members of the royal family and senior staff of the late Queen and King’s households will walk slowly behind in a dignified silence without music along a route that will take 38 minutes.
The ceremonial procession will move along The Mall, Horse Guards Road, across Horse Guards Parade, onto Whitehall and into the Palace of Westminster after 2.22pm.
Viewing areas along the route with limited capacity will open at 11am on the day, with people admitted in order of arrival time amid expected large queues, the Department for Digital, Culture, Media and Sport (DCMS) said.
If a person leaves the area their readmission cannot be guaranteed.
It will come after the Queen’s coffin is flown from Edinburgh to RAF Northolt in west London on Tuesday.
The DCMS has warned: “Please do not wait or camp in advance of the processional day.
“If you camp before this time you may be asked to move on.”
People are also advised to bring with them suitable clothing for any weather conditions, food and drink and appropriate footwear.
Tents, gazebos or camping gear, barbecues and equipment for fires and alcohol are prohibited.
Mourners must keep noise to a minimum when the procession passes them and have been told to behave appropriately, dispose of litter and follow the instructions of police and stewards or face being asked to leave.
There will also be large screens at Hyde Park where those who cannot access viewing sites can watch the procession, which will be broadcast on national television and radio.
The Archbishop of Canterbury will conduct a short service following the coffin’s arrival.