The Championship club face a possible points deduction because, following a review of their profitability and sustainability submissions, league chiefs ruled that the Rams were in breach of regulations for the three-year period ending June 30, 2018.
“The club will now be referred to an independent disciplinary commission, which will hear representations from both the EFL and Derby County,” said an EFL statement.
“As these matters are now subject to proceedings, the EFL will be making no further comment at this time.”
Spending regulations allow Championship clubs to lose £39million over a three-year period.
Derby reported combined pre-tax losses of just over £8m for the period in question, having posted a profit of £14.6m in their latest accounts.