A statement released by the German club on Thursday said the fee is "fixed" at €85 million. Sources have told ESPN Sancho will sign a five-year contract with the option of another year after undergoing a medical.
An official announcement from United followed later on Friday, that confirmed Sancho will have his medical after Euro 2020. Sancho and England are preparing for their quarterfinal against Ukraine in Rome on Saturday.
Dortmund's statement read: "The player, Jadon Sancho, is about to move from Borussia Dortmund to Manchester United Football Club.
"Both clubs and the player reached an agreement on this today. If the transfer is realized, Manchester United will pay BVB a fixed transfer fee of EUR 85.0 million.
"The contractual details now have to be coordinated and documented. The formal processing of the transfer is also subject to the successful completion of all necessary medical tests and examinations, a coordination procedure with the player's previous club and the proper and timely processing in accordance with the provisions of the FIFA Transfer Matching System."
United's statement read: "Manchester United is delighted to announce it has reached agreement in principle with Borussia Dortmund for the transfer of Jadon Sancho."
Sources have told ESPN that Sancho's former club, Manchester City, are due 15% of the profit Dortmund have made on the deal -- expected to be around €11.2m.
Speaking at a news conference on Thursday, Dortmund CEO Hans-Joachim Watzke admitted they had hoped to keep Sancho this summer, but that the 21-year-old had told the club he wanted to move to Old Trafford.
"It was the exemplary wish of Jadon," Watzke said. "We would have liked to keep him. We reached a general agreement with Manchester United on the transfer of Jadon Sancho, pending full completion, as there are still some formalities to agree on and the medical check to be completed."