United made a formal bid for the Dutch midfielder at the weekend, which the Italian club have accepted.
Inter have given the 27-year-old permission to discuss personal terms with the English champions and negotiations are expected to begin this week.
Wages could prove to be a stumbling block as Sneijder is reluctant to take a pay cut. He currently receives the equivalent of nearly £190,000 per week, which is well above United's current pay structure.
United are hopeful that they can negotiate a deal that would see Sneijder receive a large basic wage, as well as additional bonuses and signing-on fees throughout his contract.
The player is expected to fly into England later this week to begin talks, while the Reds are hopeful that they can secure a deal before the start of the Premier League season.
United start their Premier League campaign with a trip to West Brom on Sunday, August 14.