Schools in England can appeal if they can show this year's GCSE and A-level results do not reflect recent improvements, the exams watchdog says.
Ofqual's announcement comes amid concern that the manner in which grades are calculated in the absence of exams could penalise some pupils.
In Scotland there were claims that a similar system marked down poorer pupils more heavily.
Individual pupils will not be able to challenge their grades, however.
Read more in BBC News
Hundreds of English schools still at risk from crumbling concrete
Hundreds of schools in England are still at risk of collapse from crumbling concrete, according to previously unpublished figures. Official data, which the Information Commissioner’s Office (ICO)
Thousands of young people placed in council care more than 20 miles away from home, analysis shows
A third of children in council care in 2023 lived over 20 miles away from their local area, school and family – around 4,600 people in total.
£600m boost for social care next year announced in Budget
Councils’ available spending to grow by an estimated 3.2% in real terms in 2025-26, with authorities also given £250m to test new approaches in children’s