Birmingham have been fined £20,000, with a further £20,000 suspended, and warned as to their future conduct following the pitch invasion that marred their Carling Cup quarter-final victory over Aston Villa in December.
The club accepted the charge of failing to ensure no spectators or unauthorised persons were permitted to encroach on to the pitch and were handed the punishment by an independent regulatory commission.
The suspended fine will hang over the club until the end of the 2013/14 season and would be invoked were Birmingham to again fall foul of Football Association rule E20b.
Birmingham, who went on to win the Carling Cup, said in a statement: "The fine could have been much more significant but was determined after the FA commented on the professionalism adopted by Birmingham City in its preparation of the fixture, which was well documented, and the level of co-operation the club gave following the investigation and charge.
"Club officials would like to thank the FA and regulatory commission for their patience and assistance with this matter.''
More than 1,000 Birmingham supporters invaded the pitch after their side's 2-1 win at St Andrew's and confronted the 3,800 Villa fans situated in the Gil Merrick Stand at the other end of the stadium.
A flare appeared to be thrown into the section housing the Villa supporters, although it was then tossed backwards and forwards between the rival factions. Seats were also ripped out and used as missiles along with other objects.
On the night of the disturbance, Birmingham manager Alex McLeish called it a return to the "dark ages''.
The police presence in and around St Andrew's had been boosted to nearly 500 officers for the first midweek meeting between the clubs since ugly scenes seven years previously.