On Friday, the 26-year-old underwent a medical at the Premier League champions ahead of a permanent switch which will bring Phillips' twelve-year career at his boyhood club to an end.
The Yorkshire Pirlo has made over 200 appearances since he joined the Whites aged 14 and was crucial to the Marcelo Bielsa side who ended United's 16-year Premier League exile in 2020.
After taking big strides under the Argentine's stewardship, Phillips shot to national stardom last summer, performing a starring role as Gareth Southgate's England side reached the Euro 2020 final, and was later recognised as the Three Lions' Player of the Year.
For Phillips' services, the Manchester side are expected to pay £42m - rising to £45m with add-ons - while 18-year-old City prospect Darko Gyabi is set to move in the other direction and will join Leeds for a fee in the region of £5m.
News of the deal broke over a week ago and, with City keen to get Phillips bedded in before pre-season commences in 10 days time, the transfer is set to be completed by Monday at the latest.