UEFA announced on Friday that Fenerbahce breached their FFP agreement, while Porto only partially complied.
Fenerbahce face sanctions from UEFA after breaching their Financial Fair Play (FFP) agreement in 2018-19.
The Super Lig giants signed a settlement agreement in May 2016, but UEFA's Club Financial Control Body (CFCB) said on Friday the club failed to meet their break-even target.
The CFCB has consequently referred Fenerbahce to its adjudicatory chamber, which could lead to a ban from European competition.
Meanwhile, Porto will operate under transfer restrictions and a limitation on their European squad size, having "partially fulfilled" their targets.
Galatasaray and Maccabi Tel Aviv were deemed to be in compliance and will stay in the settlement regime.