Manchester City's appeal against their two-year European ban has been officially registered by the Court of Arbitration for Sport, Cas announced on Wednesday.
The Premier League club have vowed to fight the sanction imposed by Uefa on February 14 for breaching financial fair play regulations.
Although Cas did not indicate a time-frame for the appeal process, it is expected to take several months.
In a statement, Cas said: "The Court of Arbitration for Sport (Cas) has registered an appeal filed by Manchester City football club against the Union of European Football Associations (Uefa)."
City face losing hundreds of millions of pounds in prize money, TV revenue, gate receipts and sponsorship income should their appeal against the ban fail.
Last week City Football Group CEO Ferran Soriano said the club hoped to have their appeal heard by Cas before the start of next season's Champions League.
He said Uefa's charges against the club of overstating their sponsorship revenue between 2012 and 2016 and failing to cooperate with an investigation were "simply not true."