The EFL have rejected Maikel Kieftenbeld's deadline-day switch from Birmingham City to Derby County due to paperwork issues.
The two Championship sides announced the transfer half an hour after the window closed last Thursday, after Brum accepted a fee of around £300,000 for the Dutch midfielder.
In a statement today, however, the Rams confirmed that the EFL have refused to process the transfer because the required paperwork did not reach them on time.
"This scenario highlights the challenges of the transfer window," said the statement. "All clubs would prefer to complete dealings earlier, but as clubs try to fine tune their squads this inevitably creates last-minute scenarios.
"We would like to place on record our thanks for the help and assistance of Birmingham City Football Club throughout this process."
Kieftenbeld has featured in three of Birmingham's five league games so far this season.
