The West Steps of of the Cathedral will be lined by 14 Pensioners of the Royal Hospital Chelsea, aged between 65 and 90 years old.
Lady Thatcher had strong connection to the Hospital over the past 10 years.
A single half-muffled bell will toll as the cortege arrives, before the St Paul's Cathedral Guild of Ringers will ring "Stedman Cinques" with the Cathedral's bells, half-muffled, for around half an hour.
There will be two modest arrangements of white lilies and greenery at the foot of the lectern. There will also be a ring of flowers around the candle.
Orders of the Garter and Merit:
In front of the coffin as part of the procession, Michael and Amanda Thatcher - the grandchildren of Lady Thatcher - will carry cushions bearing the Insignia of the Order of the Garter and the Order of Merit, and lay them on the Dome Alta.
Music, psalms and hymns:
Lady Thatcher wanted the service to be "framed" by British music. Several traditional pieces by many of the great British composers will be played at the beginning and end of the service.
Baroness Thatcher's granddaughter Amanda and Prime Minister David Cameron will give readings during the service.
Downing Street confirmed the hymns will be He Who Would Valiant Be, Love Divine, All Loves Excelling, Psalm 84 set to the music of Johannes Brahms, and the patriotic verse I Vow To Thee My Country.
The funeral address will be delivered by the Bishop of London, the Rt Rev Richard Chartres.