More than 20,500 students received their vocational-qualification results late this year, according to England's exams regulator.
Ofqual launched a review after many had to wait for BTec, Cambridge National and Cambridge Technical grades - issued by Pearson and Oxford, Cambridge and RSA Examinations (OCR) - in August.
Some told BBC News it had thrown their university places into question.
Pearson and OCR have apologised for the delays.
Ofqual said it would now set a deadline for organisations to issue grades for vocational technical qualifications (VTQs).
