The "Special Police Service" Mechanism: Police have historically charged for services on private property (inside the stadium) as these are not considered "ordinary" policing duties.
2008 Wigan Ruling: A landmark case involving Wigan Athletic and Greater Manchester Police clarified that police can only charge for policing on the "footprint"—the area inside the ground and immediately surrounding it.
2012 Leeds United Case: Further clarified that clubs are not liable for the costs of policing outside the stadium (e.g., at train stations or city centres), which remains a cost to the public