As per Sky Sports, the notice was filed at 10.01am on Friday at a specialist companies court and Julian Pitts, Kris Wigfield and Paul Stanley of Begbies Traynor have been appointed joint-administrators.
The move will likely see Wednesday docked 12 points in a crushing blow for the side who are already dead bottom of the table. Wednesday are understood to owe in the region of £1m to HMRC in unpaid tax and reports are unsure whether their unpopular owner, Dejphon Chansiri, will now be forced into a sale.
Wednesday fans invaded the pitch earlier in the season to protest against the owner earlier this month as the side were served with a winding-up petition over the mass debts.
The side had been placed under registration embargoes in the last two seasons after being hit by a six-point deduction during the 2020/21 campaign, for breaching profit and sustainability rules in what has been a very poorly run side for some time.
A point's deduction will leave them 15 points adrift of safety and relegation looks certain. Stanley, one of the other joint administrators, said:
"There should be no interruption to the fixture schedule, and we are in close contact with the EFL to ensure the effects of this administration on the employees, supporters, the community and the players are minimised as far as possible.
"Sheffield Wednesday is a massive, historic club with a loyal fan base in a city that lives and breathes football. If more fans return to Hillsborough, the club can cover its day-to-day costs and move towards a viable sale to a new ownership capable of restoring long-term stability.
"With the right ownership structure, we are confident the club has a bright future and will meet all EFL regulatory obligations."