Reading say 'unforseeable circumstances' have led to the club being deducted six points in the Championship.
They've also had a further six-point deduction suspended until next season after financial difficulties.
That will take effect if the club fails to fulfill an agreed business plan.
It's understood the club has recorded a loss of around 70 million pounds over the last four-year period which has led to a breach of the league's rules.
The impact on their league position is significant, with the club now on 16 points - just four points outside the relegation places in 19th.
It comes after Derby County suffered a 12-point deduction earlier this year.
Club statement | EFL confirm points deduction penalty 📰
We can confirm that we have accepted the penalty of a six point deduction as a result of exceeding the EFL’s Profit and Sustainability limits.
Read the full statement here 👉
— Reading FC (@ReadingFC) November 17, 2021
"The breach of regulations was calculated across a period of four years, two of which were unavoidably yet significantly impacted by the COVID-19 pandemic" the club said in a statement.
"While there are undeniably extenuating and unforeseeable circumstances that have contributed to this breach, we accept this to be a fair and reasonable punishment and will learn the lessons from our recent past which have resulted in this deduction.
"We would like to take this opportunity to thank the EFL for their co-operation, professionalism and positive, open dialogue throughout this process."
The club's owner, Dai Yongge added, “As the owner of your club, I am naturally dismayed and disappointed to accept the punishment issued by the EFL.
"And as a fan, I too am hurt by a deduction of six points this season. However, my determination to succeed has not diminished but has amplified.
“My team and I believe this settlement is just and will still enable us to be competitive as a football club this season and beyond.
"So, in the short-term, our aim is to fight for every point there is to fight for this season.
“In the long-term, we pledge to fix the issues of the past and together build a club capable of competing with the very best and challenging for honours."