It has emerged that Man United paid £13.35m up front to the Eredivisie side before making a £6.7m payment midway through the campaign.
United will complete another £6.7m instalment for Memphis, who has suffered a mixed campaign, in the summer.
In terms of bonuses, United would have to pay PSV over £1m for winning the Premier League and another £1m for Champions League success.
Memphis garnered a reputation as one of the most exciting young players in the world at PSV but he has failed to recapture that form at Old Trafford.
He has been in and out of the side under Louis van Gaal and there are concerns for his long-term future at the club.
While Memphis has undoubtedly disappointed this term, when he has turned it on, he has been a player who has got supporters off their seats. It would be highly unwise not to give him another season to show what he can do considering the amount of money that United have paid for him.