Sgt Gareth Thursby and Pte Thomas Wroe, both of 3rd Battalion The Yorkshire Regiment, were shot by a rogue Afghan policeman on Saturday.
L/Cpl Duane Groom, of the Aldershot-based Queen's Company, 1st Battalion Grenadier Guards, died on Friday when his vehicle struck an improvised bomb.
The servicemen will be flown into RAF Brize Norton in Oxfordshire, and private ceremonies for their families will be held on the air base before the cortege leaves for the John Radcliffe Hospital in Oxford.
Married father-of-two Sgt Thursby, 29, and Pte Wroe, 18, were shot dead in the Nahr-e Saraj district of Helmand province. The men were killed at a checkpoint when a man dressed as a local Afghan policeman pretended to be injured so they would help him.
Sgt Thursby was from Skipton, North Yorkshire. Pte Wroe had family from West Yorkshire. His wife Louise described her husband as "our hero". "He was an amazing husband and father, happy, full of life and kind-hearted with a passion for his work and family," she said.
Pte Wroe was deployed to Afghanistan in July, shortly after his 18th birthday. He leaves his parents, Michael and Claire, and sister Demi, from Holmfirth, West Yorkshire. His parents described their son as a "fun-loving guy who would do anything for anyone".
L/Cpl Groom, 32, who was born in Suva City, Fiji, was protecting his Afghan and British colleagues in the Nahr-e Saraj district when he was killed.
Lt Col James Bowder, Commanding Officer, 1st Battalion Grenadier Guards, said L/Cpl Groom was "an outstanding soldier in every respect. We are all tremendously proud of what he achieved during his time in the regiment, and particularly out here in Afghanistan where he contributed so much."
The soldiers' deaths take the total of British military personnel killed in Afghanistan to 430 since operations began 2001.