The occasion will by like no other royal service, with a limited number of attendees wearing masks and social distancing rules in place.
A Buckingham Palace spokesperson confirmed that it will not be a state occasion, in accordance with the Duke’s wishes, but a ceremonial royal funeral in line with the Queen Mother’s funeral in 2002.
When is it?
The funeral begins at 2.40pm on Saturday 17 April, when the coffin will be placed onto a modified Land Rover designed by the Duke of Edinburgh himself prior to his death.
A procession will then begin at 2.45pm when the Prince of Wales and senior members of the royal family will follow the coffin on foot as it is driven to St George’s Chapel.
It is understood the Queen will not take part in the procession.
The funeral service will then start at 3pm, when a national minute's silence for the Duke will also be observed.
Who will be attending?
Only 30 people - expected to be the Duke's children, grandchildren and other close family - will attend as guests.
There would have normally been around 800 members in the congregation inside St George’s Chapel.
The Duchess of Sussex, who is now heavily pregnant, has been advised by her physician not to travel to the UK for the funeral, a Palace spokesman said.
How can I watch it?
All public elements of the funeral have been cancelled, it will be televised but take place entirely in the grounds of the castle, the Palace said.
The ceremony will be shown live on the UK’s main channels including BBC One and on BBC iPlayer.
What else do we know about the preparations?
Royal Navy posted a tweet on Thursday saying Royal Navy sailors and Royal Marines have been rehearsing as preparations are being finalised ahead of the funeral this Saturday.
It is understood the route of the procession will be lined by representatives drawn from the Royal Navy, the Royal Marines, the Highlanders, 4th Battalion Royal Regiment of Scotland and the Royal Air Force.
The Queen has decided that senior royals attending the service should be in civilian clothing rather than military uniform, according to reports.
The move means that Prince Harry who lost his military titles after stepping down as a senior will not have to be one of the only close family members not in uniform at Saturday's service.
The Scottish Grand National at Ayr has been moved from this Saturday to Sunday to avoid clashing with the service and "as a mark of respect" to the Duke’s funeral.
The British Horseracing Authority has said the Spring Trials at Newbury have also been moved to Sunday.