The Department for Culture, Media and Sport has said the historic occasion will be shown in various locations - from London s Hyde Park to Coleraine Town Hall in Northern Ireland.
With the line at around 3.5 miles long, mourners who have made the last-minute scramble to see the Queen s coffin this evening can expect to queue for around seven hours.
The two young siblings, who are second and third in line to the throne, will enter the church behind Her Majesty s coffin as the funeral procession enters Westminster Abbey on Monday morning.