Pogba, 23, completed a medical in Manchester on Monday before signing a five-year contract with an option for another year.
United have agreed a world record £89m fee with Juventus with a further £4.2m in potential add-ons.
On top of the transfer fee paid to the Italian champions, the Red Devils will also pay 100 per cent of the money due to Pogba’s agent, Mino Raiola, who had agreed a 20 per cent sell-on fee when the France international signed his last contract in 2014.
Ed Woodward, United’s executive vice-chairman, is understood to have attempted negotiations over the £18.6m that would be due to Raiola and sources are remaining tight-lipped on exactly how much the super-agent will earn.
Pogba, 23, has agreed an enormous £300,000-a-week salary package including bonuses and will become United’s joint top-earner along with captain Wayne Rooney.
That works out as up to £15.6m-a-year and £78m over the course of his five-year contract if Pogba triggers all of the bonus payments in the agreement.
It brings the total cost of the deal up to a maximum of £190m, with United hoping that trophies and commercial deals will mean the eye-watering sums will prove to be value for money.
Pogba initially left United to join Juventus in 2012 for just an £800,000 compensation fee after he became frustrated with a lack of playing opportunities under Sir Alex Ferguson and refused to sign a new contract.
United have flexed their financial muscle in the summer transfer window despite missing out on qualification for this season’s Champions League.
New manager Jose Mourinho has landed Pogba as his fourth and final “priority” signing this summer having already brought Zlatan Ibrahimovic, Henrikh Mkhitaryan and Eric Bailly to Old Trafford.
United won the Community Shield on Sunday with a 2-1 victory over Premier League champions Leicester at Wembley and play their first league fixture away at Bournemouth on Sunday.