They said the FFP rules, drawn up by European football's governing body, were fully compliant with European law.
The central principle of FFP is that clubs should "live within their means" or break even based on football-related income at least matching their football-related expenditure.
UEFA and the EC have acted to stop any club mounting a challenge in court to the FFP rules, which come fully into force in 2013-14 with any sanctions imposed in the 2014-15 season.
UEFA president Michel Platini believes the joint statement is a significant step in strengthening the policy, saying: "Our statement confirms that UEFA's Financial Fair Play regulations are fully consistent with EU State aid policy."
Joaquin Almunia, vice-president of the EC and the Commissioner for Competition added:
"I fully support the objectives of UEFA's FFP rules as I believe it is essential for football clubs to have a solid financial foundation.
"The UEFA rules will protect the interests of individual clubs and players as well as football in Europe as a whole."
Almunia, who has agreed the 14-point statement with Platini, would rule on any complaints and his comments make it clear that there would be little sense in clubs challenging the ruling.
Some observers have questioned whether the FFP rules can work, but the UEFA/EC joint agreement means there will be no room for clubs to manouevre their way out of the framework.
At present, many clubs have huge debts which need to be off their books when FFP comes fully into force or else they will risk UEFA sanctions which could include disqualification from the Champions and Europa League competitions.
UEFA's general secretary Gianni Infantino told Reuters: "Let us be clear this is not a new law. But it reaffirms what we have always said that the FFP rules are legal and in accordance with European legislation."
Earlier, Infantino told a news conference following a two-day UEFA executive committee meeting in the Turkish capital:
"It certainly reaffirms what we have always said that financial fair play is legal.
"If anyone was thinking of filing some sort of complaint saying FFP somehow restricts European competition law they would have to file it to the Commission. This is a big milestone in the enforcement of the break-even principle."
What FFP and Wednesday's joint statement cannot prevent at present, however, are the types of financial problems affecting clubs such as Rangers in Scotland, Portsmouth in the English Championship and Servette and Neuchatel Xamax in Switzerland, where poor management has led to difficulties.
Asked if it was time for UEFA to oversee who could and could not take control of Europe's senior clubs, Infantino replied:
"It is not our ambition to dictate everything everywhere. We hope we can convince every league, every association and every club in Europe to implement the same rules and to make sure there is a stricter control as it is really a pity and sad to see what is happening today in Switzerland, and in Scotland where some traditional clubs are going bust for whatever reason.
"This shows more control is needed, more enforcement is needed, but this cannot be done by UEFA but by everybody in a responsible way and our job is to convince everyone to follow the same principles and the same rules which we have started to do.
"If we can take one positive aspect from these cases, it is that they open everyone's eyes and show that something needs to be done."