Financial regulation in club football rarely stops a signing outright. Its effect is on the shape of deals and on the timing of them, and both are visible every window.
Fees are spread, wages are not
A transfer fee is written down across the length of the contract rather than charged in the year it is paid, so a long contract reduces the annual accounting cost of a signing.
Wages, by contrast, hit the accounts in full each year, which makes salary the harder constraint for a club close to a limit.
Understanding this explains why clubs offered unusually long contracts, and why governing bodies later capped how many years a fee could be spread over.
Selling academy players is disproportionately valuable
A player developed internally carries almost no remaining book value, because there was no fee to write down in the first place.
Selling him therefore records nearly the entire fee as profit in that year, while selling a recently bought player only records the amount above his remaining value.
That asymmetry is why clubs under pressure sell homegrown players who are contributing rather than expensive signings who are not.
Accounting dates drive the calendar
Compliance is assessed against a financial year end, and clubs close to a limit need transactions completed before that date.
This produces bursts of activity that look strategically odd but are simply deadline-driven, including sales agreed hurriedly at the end of June.
It also explains swaps between clubs that both need profit, where two players move in opposite directions for similar fees and each side books a gain.
Squad limits work differently from spending limits
Rules capping total wages as a proportion of revenue restrict how much a club can commit, regardless of whether the money exists.
A club with a wealthy owner is therefore constrained by what it earns rather than by what it could afford, which was the intention.
Revenue growth becomes the route to spending power, which pushes clubs towards commercial expansion and towards competitions that pay well.
Why enforcement remains contested
Valuing a related-party sponsorship or an intra-group transfer requires judgement, and clubs and regulators frequently disagree about what a fair figure is.
Penalties have ranged from fines to points deductions, and appeals are common because the sums and the sporting consequences are both large.
The specifics vary by competition and are revised regularly, so the practical rules a club plans around are rarely the ones it planned around three years earlier.