The 's decision follows a request from an undisclosed source to the BBC for the total annual staff costs for and the annual value of performers' contracts.
The BBC refused to release the information maintaining that it was not covered by the scope of the act, but its argument has been dismissed by assistant commissioner Anne Jones.
She considers that the information was held by the BBC for operational purposes such as financial and administrative reasons and therefore it does fall within the scope of the act.
The BBC also highlighted that the disclosure of the annual staff costs would prejudice commercial interests and could, in the future, lead to entire programme budgets being disclosed.
It said that this could have an effect on bids from independent production companies, but the ICO said the argument is flawed because it is unlikely that all separate cost elements of an in-house production will be disclosed under the freedom of information act.
The ICO concluded that it was not satisfied that disclosing the annual staff costs would prejudice the BBC's commercial interests.
The BBC was, however, successful in arguing that it should not have to reveal the salaries of the soap's actors, which include stars such as Barbara Windsor, Steve McFadden and Patsy Palmer.
The ICO agreed that the BBC was correct to withhold information regarding the average and range of values of performer's contracts as providing the information to the complainant would exceed the cost limit set out under the act.