Topshop's UK parent company Arcadia Fashion Group has entered administration, with 444 stores and more than 13,000 jobs at risk.
The news comes after Topshop closed its final store in Australia in March this year.
Suffering the blows of COVID-19, the business appointed Deloitte UK to seek a new owner for the business.
"This is an incredibly sad day for all of our colleagues as well as our suppliers and our many other stakeholders," Arcadia CEO Ian Grabiner said.
"The impact of the COVID-19 pandemic including the forced closure of our stores for prolonged periods has severely impacted on trading across all of our brands.
"Throughout this immensely challenging time our priority has been to protect jobs and preserve the financial stability of the Group in the hope that we could ride out the pandemic and come out fighting on the other side.
"Ultimately, however, in the face of the most difficult trading conditions we have ever experienced, the obstacles we encountered were far too severe.
"Our priority now is to work closely with the administrators to deliver the best possible outcome for all our stakeholders, in particular our hard-working employees across the Group," he said.
Deloitte joint administrator Matt Smith added that the challenges that face bricks and mortar retailers, both before and during the pandemic took a toll on the business.
"Arcadia sits at the heart of the High Street, and has been striving to combat the impact of COVID-19 throughout this year.
"Now the effect of the lockdowns, combined with broader challenges facing bricks and mortar retailers, have resulted in a critical funding requirement for the Group and today’s administration.
"We will now work with the existing management team and broader stakeholders to assess all options available for the future of the Group’s businesses," he said.
Arcadia Group operates the brands Topshop, Topman, Miss Selfridge, Dorothy Perkins, Burton, Wallis, Outfit and Evans.
The Group was acquired in 2002 by British businessman Sir Philip Green for £850 million.
The business' stores will continue trading during the administration process.