Manchester City have been found guilty of all 115 charges of serious breaches of Premier League regulations, the Premier League confirmed in a 1545-word statement on Tuesday.
City, who denied all charges, have until Friday Oct. 2 to exercise their right to an appeal.
Richard Masters, chief executive of the Premier League, said: "The core decision establishes the facts of what happened at Manchester City during this period. It details how the club systematically broke Premier League Rules for nearly a decade.
"It also vindicates the Premier League's decision to pursue this case against Manchester City. While the process to date has been both long and difficult, the League has remained determined that the facts be established independently.
"It is a key responsibility of the Premier League to ensure that the Rules, approved by the clubs themselves, are upheld to protect the integrity of the competition. It is paramount that the League remains competitive and fair for all clubs and for the fans. We take that role extremely seriously.
"This disciplinary case, and this decision, are the most significant in Premier League history. There are elements of the case that remain to be decided, including, importantly, what sanction must follow for these breaches. Now we have the Commission's decision, we are committed to moving swiftly through the remainder of the process, to provide certainty for the League, our clubs and fans."
A City statement read: "Manchester City FC is both disappointed and surprised by the opinion of the Premier League Commission, that has been published today. The Club is innocent of the accusations made by the Premier League and a comprehensive body of irrefutable evidence exists in support of all of its positions, relating to this case. The Club will therefore be relentless, and where necessary proactive, in any and all appropriate regulatory and legal forums.
"The Premier League process remains ongoing, with significant elements uncompleted. Manchester City FC will now pursue the appeal avenues open to it, on the basis that the opinion contains clear material errors, of law, principle and fact, and is unsafe.
"The Club has diligently respected due process for eight years on the basis that the Premier League Board and Executive would behave as an independent, impartial and fair-minded regulator, free from partisan influence.
"The Club is obviously restricted in what it can say further until all future proceedings are complete."