UEFA secretary general Gianni Infantino said 76 European clubs out of 237 originally assessed had been asked to submit additional information about their finances ahead of the new rules which come into full effect next season.
In April, the Club Financial Control Board (CFCB), which is responsible for implementing the new rules, will announce which of those cases have been dismissed and which will be referred to its disciplinary panel for sanctions.
The final decisions, which could include bans from European competition in the most serious cases, will be announced in June.
UEFA's so-called financial fair play rules are being introduced to force clubs to live within their means and prevent those with rich owners from simply spending their way to success.
In principle, clubs cannot spend more than their generated revenue although they are allowed cash injections of up to 45 million euros ($62.2 million) over three years. Spending on training facilities and youth development is exempt.
"UEFA is taking the lead to protect European football from greed, from reckless spending and financial insanity," Infantino told reporters.
"Financial Fair Play basically proposes helping the clubs to live within their revenues in a sustainable way," he added.
"UEFA is not seeking to exclude or isolate clubs, Financial Fair Play is to help the clubs but on the other hand UEFA is not afraid to take the necessary measures to protect the game."
UEFA said all the 237 clubs who qualified for European competition this season have been assessed. Of those, 103 were ruled exempt as their revenue or income was below the minimum of 5 million euros annually.
UEFA's head of legal affairs Alasdair Bell stressed that CFCB was an independent body.
"We have established an independent body and when we say its independent we mean it," he said. "This is the separation of powers, this is modern sports governance."
"You have to have confidence in your institutions; we have set up a new kind of institution composed of expert people, not people from football.
"They are leading people from economics and politics and we believe these are the right people to impose the rules in a correct and impartial way."
"It involves a certain degree of risk because we can't tell the people what to do, if we did them exactly what to do, they wouldn't be independent," he said
"This is the price you pay for having modern governance in football, it's a price we are willing to pay."
Bell said that he expected some clubs to take their case to the Court of Arbitration for Sport (CAS) if they were sanctioned.
"This will not surprise us if some of our decisions our contested. We are not afraid of them being contested, we have confidence in the people taking the decisions.
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