Secondary school spending on exam fees has shot up by an inflation-busting 6.7 per cent, or #163;17.7 million, in a single year to a total annual bill of #163;281 million.
The latest figures published by exams regulator Ofqual for 200809 reveal that English secondaries have had to shoulder an 82 per cent increase in fees paid to exam boards in just six years.
Government statistics show that inflation rose by just 12 per cent over the same period.
John Dunford, Association of School and College Leaders (ASCL) general secretary, said: "This huge increase in exam fees far outstrips the increase in school funding over every comparable recent period. It has got to stop.
"This juggernaut will only be brought to a halt with a radical review of exams, which should surely give more weight to the professional judgment of the teacher as part of the final grade."
One reason for the increase could be a larger number of re-sits and different qualifications being used by schools. But Ofqual's report also reveals a large rise in fees for individual exams.
The watchdog calculated that the average fee for an English GCSE rose from #163;23.74 in 200607 to #163;27.41 in 201011. That represents a 16 per cent increase, nearly double the 8.5 per cent rise in inflation over the same period.
The average prices of GCSEs in maths, science, French, history, and art and design went up by similar amounts. Over the same period the average fee for a maths A-level rose by more than 12 per cent.
In recent years another reason given for such big increases in fees has been the growth of modularisation, meaning there are more papers to be sat and more opportunities for re-sits. But that trend should have started to slow with the reduction in A-level modules from six to four in 200809.
Studies have shown that schools now spend more on exams than books, with the bill for external tests now bigger than any other item except staffing.
Ofqual has been given the legal power to cap exam fees. But after protests from exam boards that this would stifle innovation, it was ruled that the watchdog could only cap a fee for a particular exam if it was satisfied the limit was necessary to "secure value for money".
The exam boards said changes such as the introduction of Diplomas and new GCSEs and A-levels meant increased costs. OCR and AQA - which said it kept fees as low as possible - both stressed they were non-profit, with any surpluses re-invested.
Edexcel said it offered "excellent value for money" and that, when curriculum changes were taken into account, price changes were below inflation for the last two academic years.
Ofqual said it would continue to review the level of exam fees.
BATTLE OF THE BOARDS
In 200809 the Assessment and Qualifications Alliance (AQA) continued to be the biggest A-level provider, despite its market share dropping slightly from 42 per cent to 41 per cent. The share of Oxford, Cambridge and RSA examinations (OCR) also dropped, from 26 per cent to 25 per cent, while Edexcel rose from 24 per cent to 25 per cent.
At GCSE in the same year, AQA was also the biggest board despite its share falling from 47 per cent to 46 per cent; OCR and Edexcel both retained 21 per cent shares.
In 2008, Edexcel's annual income dropped from #163;225 million to #163;205.7 million. AQA's also fell from #163;144.9 million to #163;144.4 million, while OCR saw a large rise, from #163;106.7 million to #163;120.8 million.