"When there is a 1.2 billion euro deficit in European football, there is danger," the Frenchman told sports daily L'Equipe on Friday.
"Clubs know the rules and I will write to them before summer to remind them that our credibility will force us to go all the way. If the question is to know whether I will have the courage to punish clubs of high repute? the answer is yes."
Last year, Platini said that clubs who continued to overspend would be penalised, explaining they could face exclusion from the Champions League or the Europa League for non-compliance.
"If, in 2015, clubs (still) do not follow the rules, the disciplinary committee, which is independent, will impose sanctions," Platini added.
Under the law coming into effect for the 2012/13 season, only clubs that are financially stable will be allowed to play in Europe's elite competitions.
Clubs must break even over a rolling three-year period if they wish to play in those tournaments and will also be assessed on a risk basis, taking into account salaries and debt.
Platini, 55, is running unopposed as he bids for a second term as UEFA president.
