Agents' fees
Also called
Clubs pay agents when they sign a player, renew a contract or sell a player. Those payments are part of the cost of running a squad, so SCR counts them in the numerator alongside wages and amortisation.
The Football Association publishes annual totals of intermediary payments by club, which is the usual public source. It is a smaller line than wages or amortisation, but for clubs with heavy transfer activity it is not trivial.
On this site, agents' fees are stored as a separate component of each Premier League club's squad cost so that the arithmetic can be checked and corrected component by component.