Premier League's transfer deadline day on September 1, 2025, was filled with drama, headlined by Alexander Isak's record-breaking move to Liverpool and a late collapse in Marc Guehi's transfer to the same club.

Alexander Isak's protracted transfer saga finally concluded with Liverpool agreeing to pay Newcastle a British-record £125 million for the Swedish striker. The deal eclipses the previous record of £115 million paid by Chelsea for Moises Caicedo. Isak is expected to sign a six-year contract with a £300,000-a-week salary. The 25-year-old reportedly forced the move by refusing to train with Newcastle after Liverpool's initial £110 million bid was rejected. Isak felt Newcastle broke a commitment that he could leave if a suitable offer arrived from a big club and rejected attempts to negotiate a new contract. To fill the void left by Isak, Newcastle is reportedly signing Yoane Wissa from Brentford for £55 million. Liverpool's acquisition of Isak took their summer spending to over £440 million, having already signed Florian Wirtz for over £100 million.

Liverpool's pursuit of Crystal Palace defender Marc Guehi ended in disappointment despite agreeing to a fee of around £35 million. Liverpool reportedly submitted a deal sheet to the Premier League to allow extra time to complete the transfer. However, the deal collapsed because Crystal Palace were unable to secure a replacement for their captain. Crystal Palace's manager, Oliver Glasner, wanted to keep his captain and the club pulled out of the deal. Liverpool had been linked with Guehi for a month, and he had reportedly agreed to personal terms.

Other notable deadline day deals included Gianluigi Donnarumma's move to Manchester City from PSG and Ederson potentially going the other way to Fenerbahce. Tottenham secured Randal Kolo Muani on loan from PSG, while Manchester United signed goalkeeper Senne Lammens from Royal Antwerp. Arsenal also completed a loan deal for Piero Hincapie from Bayer Leverkusen. Sunderland are set to sign Brian Brobbey from Ajax for around £20 million.

With Premier League clubs spending millions, this transfer window is arguably the most expensive ever.