Chelsea have been fined A$56 million by UEFA for breaches of their financial rules, while Aston Villa, Barcelona and Olympique Lyonnais were also levied with large fines.
The punishments come with the potential for far harsher fines down the road, with Chelsea, who agreed to a four-year settlement with UEFA's Club Financial Control Body (CFCB), risking being hit with a further A$108 million if they do not get their finances in order.
Barcelona must pay a $A27 million fine, but could potentially face $A108 million in total, with UEFA, European soccer's governing body, fining Lyon $A22.5 million and Aston Villa $A20 million.
Chelsea's fines were split into $A36 million for not complying with the football earnings rule and $A20 million for breaching the squad cost rule, while Aston Villa were fined $A9 million and $A11 million for their respective rule violations.
The clubs are also subject to a restriction on the registration of new players on their List A for UEFA club competitions such as the Champions League and Europa League.
The teams accepted settlement agreements which cover periods of two, three or four years, with the clubs' final targets to be fully compliant with the football earnings rule by the end of their specific settlement period.
Lyon agreed on an exclusion from the 2025/26 UEFA club competitions should the French authority confirm the club's relegation to Ligue 2.
Chelsea sold their women's team for $A423 million to a parent company Blueco, which helped to balance their spending and avoid huge losses, despite their lavish spending in the transfer market under owner Todd Boehly.
UEFA, however, refused to count the sale of the team as an asset.
The club also sold two hotels to a Âsister company in a deal that appears to have helped the club to remain compliant with profitability and sustainability rules.
Premier League clubs are not permitted to have losses of more than $A219 million over a three-year period.