Saracens have escaped with a 50,000 euros (£42,500) fine after admitting they fielded an ineligible player in their Champions Cup match against Racing 92 last month.
An independent disciplinary committee deemed the fine – half of which is suspended – was sufficient after accepting the situation occurred due to an administrative error.
Saracens fielded prop Titi Lamositele in the match despite the American international's work permit having expired on the day before.
Saracens had feared being thrown out of the competition, having already been relegated from the Premiership due to salary cap breaches.
But committee chairman Roger Morris said in a statement: "Following careful consideration of a complaint involving a player who has been contracted to Saracens since 2014, and who remains contracted to the club, the committee believes that this was an unfortunate sequence of events brought about by an administrative oversight.
"However, Saracens are in breach of the Disciplinary Rules of the Heineken Champions Cup, and that breach constitutes misconduct which can be proportionately dealt with by way of a financial penalty."