Birmingham have been fined by the Premier League after they were found guilty of a discriminatory pricing policy against away supporters at St Andrews last season.
The ruling comes after Sunderland pursued the matter with the Premier League following complaints from their fans over pricing of tickets for a game at Birmingham last August.
A Premier League-appointed independent commission ruled that Birmingham were guilty of discriminatory pricing against away fans at a number of games during the 200-08 season.
The commission decided that the price the Blues charged to away fans was higher than that charged to their own fans for a comparable standard of accommodation.
Birmingham were in breach of Premier League Rule J(9) and the club was handed a fine of £30,000 and ordered to pay costs.
Premier League chief spokesman Dan Johnson said: "Fans of all Premier League clubs deserve to be treated in an open and fair manner when it comes to the pricing of away tickets, and we are pleased the independent commission recognised the important of this rule."
The charges relate to the pricing of 10 matches at St Andrews last season and Birmingham have decided not to appeal against the commission's ruling.
Sunderland chief executive Peter Walker was pleased with the outcome of the result of the decision and told www.safc.com: "This was clearly something our fans felt strongly about so we were keen to have the matter investigated on their behalf.
"It has taken some time to resolve but we are pleased that out fans' grievance has been fully acknowledged."
The Football Supporters' Federation also applauded the move to punish City and FSF chief executive Malcolm Clarke has called on Birmingham to either refund the money to the fans they have taken extra money from or donate it to football charities.
"We congratulate the Premier League on taking this action - it proves the importance of fans making complaints when the rules are broken, something the FSF will always be willing to help supporters do," Clarke said.
"The principle of away fans not being exploited is very important to us. We hope that this £30,000 fine will prevent any reoccurrence by them or any other clubs.
"But it is not right that Birmingham should keep the money they made from this.
"We call upon them to now refund the excess charges to the clubs concerned, so that they can return cash to the fans who paid over the odds.Reuse content