The Belgian was reunited with his former Toffees manager at Old Trafford on deadline day, with some questioning United's approach knowing with the midfielder has a release clause of £23.5m in July.
This prompted speculation that Fellaini paid the £4m difference to force an exit from Everton, but the club's director of communication, Alan Myers, stressed that there is no truth in such speculation.
"For those asking: No Felli [Fellaini] did NOT pay £4m of the transfer fee! The buying club will pay £27.5m," Myers wrote on Twitter.
Fellaini was a huge success in his five years at Goodison Park, making 177 appearances and scoring 33 times.