Uefa general secretary Gianni Infantino has warned clubs that they must adapt to Financial Fair Play (FFP) rules or face sanctions.
European football's governing body intend to implement new laws in 2018 that will see clubs required to bring their annual losses below €10 million.
The massive outlay of clubs like Monaco, Paris Saint-Germain and Manchester City this summer have prompted many to ask if the rules will actually be enforced, but Infantino insists that there will be no leniency shown towards any side whose books are not in order.
"Big clubs as well as small clubs, the rules are there," he told BBC Radio 5 Live. "A year ago, we warned that this is the last wake-up call for the clubs and that the rules have teeth.
"The break-even rule will enter into force next season, taking into account the figures of this season and last season.
"The clubs know the rules. If they haven't generated enough revenue to perform these transfers, then there will be sanctions - sanctions which could be a warning or a fine or a restriction on registering new players or, finally, an exclusion.
"The Financial Fair Play rules have been introduced and implemented not to punish clubs but to help the clubs."
Meanwhile, Infantino admitted that he hopes that the new regulations might pave the way for supporters having a greater say in how their clubs are run.
"It's important to keep the fans on board," he reasoned. "Fans are the only ones who remain loyal throughout their life to the club.
"Everybody else sooner or later changes - players, managers, even owners - so a dialogue with fans to find the right balance is a good thing."