Paris Saint-Germain, Inter Milan and Juventus are among clubs who were handed fines by UEFA on Friday for breaches of Financial Fair Play (FFP) rules, European football's governing body said.
Qatar-owned French champions PSG were given the biggest fine of 10 million euros ($10m) while Roma, AC Milan, Besiktas, Marseille and Monaco were also punished.
The fines were dished out after analysis of the financial years from 2018 to 2022 by UEFA's Club Financial Control Body found they had all failed to comply with the "break-even requirement".
Roma must pay five million euros and Inter four million euros, while Juventus were fined 3.5 million euros and Milan two million euros.
Besiktas must pay 600,000 euros. The lowest fines went to Marseille and Monaco, who must pay 300,000 euros each.
However, UEFA said that clubs were only being asked to pay 15 percent of total agreed "financial contributions".
Therefore, PSG's fine could rise to 65 million euros, if they fail to comply with the settlement reached with UEFA for the next three years, while Roma's fine could reach 35 million euros.
Most of the clubs agreed to three-year settlement periods, but Roma and Inter both chose to have four years to meet UEFA's targets, which means they cannot register new players for European competition this season.
"Under the three-year settlement agreement, clubs agree to comply with the football earning rule during the 2025/26 season," UEFA said.
"They undertake to reach intermediate annual targets, and to the application of conditional financial and sporting measures should these targets not be met."
UEFA announced earlier this year that it was phasing out its existing Financial Fair Play rules, which were introduced in 2010 and have allowed clubs to report losses of no more than 30 million euros over a three-year period.
However, the 2020 and 2021 financial years have been assessed as one unified period due to the impact of the pandemic.
FFP is being replaced by new licensing and "sustainability" regulations which will allow clubs to report losses of 60 million euros over three years, and the permitted figure can even reach 90 million euros for a club "in good financial health".
PSG have been targeted by UEFA in relation to FFP in the past. The club were cleared of wrongdoing in 2018 following an investigation triggered by them splashing out 400 million euros to buy Neymar and Kylian Mbappe both in August 2017.
Before that, in 2014, PSG were fined 60 million euros for rule breaches, albeit two-thirds of that amount was suspended.
PSG president Nasser al-Khelaifi, who is the chairman of the powerful European Club Association, also sits on UEFA's Executive Committee.