Exeter have been deducted two Aviva Premiership points and fined £5,000 after fielding too many overseas players against Leeds Carnegie last month.
The ruling was handed down by a joint Rugby Football Union and Premiership Rugby panel comprising Rugby Football Union disciplinary officer Judge Jeff Blackett, RFU board director Jonathan Dance and Premiership Rugby chief executive Mark McCafferty.
Premiership clubs are only allowed to include two players from outside Europe, Africa, the Caribbean and the Pacific islands in their 23-man match-day squads, but the Chiefs used three in the 27-22 defeat at Headingley.
A points deduction was expected but is unlikely to have any major bearing on Exeter's first season in the Premiership.
They currently sit ninth in the standings, ahead of Sale, Newcastle and relegation favourites Leeds.
They will now slip from 41 to 39 points, still seven above the Sharks in 10th.
The maximum punishment for a breach of this kind is a 10-point deduction, but that may only be applied if the disciplinary board believe there was an attempt to deliberately gain a competitive advantage.
That never looked a likely conclusion given one of the three players, Ignacio Mieres, was an unused substitute.
Of the other two players, Hoane Tui and winger Nemani Nadolo, the latter would be exempt from overseas registration as he is Fijian, but he used an Australian passport when securing his work permit earlier this year.