They pay some of the bill, which is agreed prior to the season so additional numbers is not something that'll automatically paid for by the club.the club pays for policing. Certain games that are high risk need extra police and stewarding and it’s been that way for years. The derby yesterday is an example with matrix vans still sitting on county road til after 8pm . That’s not a regular thing for every game is it ? Oh and the police love a bit of football overtime so don’t be so naive.
The belief that clubs pay all their bills is a complete and utter fallacy. Just look at the issues down in the Met, where clubs contribute much less.