Saracens are facing the "devastating" threat of being docked 35 points and fined over £5m for multiple breaches of Premiership Rugby's salary cap regulations.
Club chairman Nigel Wray says the club, who are back-to-back Premiership champions and reigning European champions, will appeal against what they describe as "heavy-handed" punishments.
The launching of an appeal means the sanctions will be suspended.
Had the points penalty come into effect immediately, it would have left the team on -26 points after three games played in the early Gallagher Premiership standings.
Should the appeal fail and the original sanctions are upheld, the club are liable for the full £5,360,272.31 within 21 days of the decision under Premiership Rugby regulations - a huge financial penalty alongside the sporting sanction.
Wray said in a statement: "For over 25 years, I have put my heart and soul into the game I love. Together we have created something incredibly special with the Saracens family, both on and off the field.
"This is absolutely devastating for everyone associated with this amazing group of players, staff, partners and fans."
An independent panel led by barrister Lord Dyson found the club had failed to disclose payments to players in each of the 2016-17, 2017-18 and 2018-19 seasons, and had also exceeded the ceiling for payments to senior players.
The panel was established after a nine-month Premiership Rugby investigation led to charges being brought in June. The panel upheld all the charges.
Wray added: "It has been acknowledged by the panel that we never deliberately sought to mislead anyone or breach the cap and that's why it feels like the rug is being completely pulled out from under our feet. We will appeal all the findings."