On Christmas Eve last year it was announced the British billionaire businessman, the chairman of chemicals company INEOS, had agreed a deal to buy 25 percent of the club, including investing a further $300 million (£238 million) into infrastructure on top of his $1.3billion purchase price.
That deal was ratified in February and the US Securities and Exchange Commission has confirmed the final $100 million (£79.3 million) was paid on Wednesday.
The SEC filing published Thursday also confirmed that all of Ratcliffe's shares in United are being transferred to INEOS from Trawlers Ltd, which bought the stake from the US-based Glazer family, who remain the club's majority owners.
With INEOS now in charge of United's football operations, Ratcliffe has made what he calls "difficult and unpopular decisions" since becoming co-owner at a club he felt had become "mediocre".
Some 250 members of staff have left, while former United manager Alex Ferguson is being stripped of his ambassadorial role at the club.
Meanwhile, the mid-season decision to increase prices of remaining home tickets to £66 per match, without any concessions for children or pensioners, sparked anger and protests among United fans.
But Ratcliffe, 72, recently told the United We Stand fanzine the club "need to sweat every pound" if they are to return to former glories, with the team currently looking to climb from 13th place in the Premier League table under newly-appointed manager Ruben Amorim.
"To get Manchester United to where we need to get it - it's a bit like the country (Britain) - we have to make some difficult and unpopular decisions," said Ratcliffe.
"If you shy away from the difficult decisions then nothing much is going to change.
"We won't get everything right and it won't happen overnight, but we haven't been sat on our hands for nine months. There has been a lot of change."