More than 15,000 GCSE grades were changed last year as the number of queries from schools rose, figures showed today.
After last summer's exams, secondary schools in England, Wales and Northern Ireland submitted 94,817 GCSE grades for re-marking - up from 85,981 in 2008.
Of these inquiries, around one in six GCSE grades - 15,009 in total (15.8%) - were altered.
In 2008, 15,825 grades were changed.
The statistics, published by exams regulator Ofqual, also reveal that 53,524 A-level grades were sent back last year, resulting in around one in eight - 6,160 in total (11.5%) being changed.
The year before, 5,705 grades were altered.
All of the grades could have been marked down as well as up.
The statistics also show that 14,157 A-level grades were submitted as a "high priority" to be re-marked, because teenagers were waiting on the results to confirm places at college or university.
This was an increase from 12,998 submissions in 2008.
Of those submitted as a high priority following the 2009 exams, one in ten, 1,449 grades (10%) were changed. This is compared to 1,202 that were changed in 2008.
Ofqual chair Kathleen Tattersall said: "These figures provide invaluable information regarding the examination season. As regulator it is our role to ensure that fair systems are in place and that these are followed correctly.
"We are continuing to regulate awarding organisations to check that they have good quality assurance systems in place to ensure that any incorrect marking is quickly identified."Reuse content