Nine of the 12 clubs that attempted to launch the European Super League made amends with UEFA on Friday by formally ditching the project.
Each of the nine clubs submitted a "club commitment declaration" to reintegrate, UEFA said in a statement.
Barcelona, Juventus, and Real Madrid have yet to concede ground and now face action from UEFA's disciplinary bodies.
The other nine clubs - AC Milan, Arsenal, Atletico Madrid, Chelsea, Inter Milan, Liverpool, Manchester City, Manchester United, and Tottenham - will forfeit 5% of any revenue they receive from UEFA for one season. They'll also face fines of up to €100 million if they attempt to break away in the future.
Additionally, the teams will contribute a combined €15 million to children's and grassroots football.
"These clubs recognized their mistakes quickly and have taken action to demonstrate their contrition and future commitment to European football," UEFA president Aleksander Ceferin said. "The same cannot be said for the clubs that remain involved in the so-called Super League, and UEFA will deal with those clubs subsequently."
Ceferin previously threatened to ban any team that refuses to renounce the Super League from future Champions League and Europa League competitions.
Madrid, along with bitter rivals Barcelona and Italian side Juventus, are now threatening to pursue legal action against the teams that abandoned the project, according to The New York Times' Tariq Panja.
Madrid president Florentino Perez said the 12 clubs couldn't officially withdraw from the Super League because they had signed "binding contracts."
However, the withdrawal of nine clubs can force the termination of the Super League, according to a contract obtained by The New York Times.
The Super League collapsed within two days of its announcement on April 18. England's Big 6 clubs reversed course after intense backlash from fans, former players, and politicians. Milan, Inter, and Atletico Madrid soon followed.