An apology has been issued to students at the University of Exeter Business School after they were forced to pay to sit examinations managed by private companies.
Students studying modules in microeconomics and financial accounting at the school are required to take weekly online assessments set by Aplia and Accounting Lab.
To sit the tests, they need a code, which can be bought for about £17 online or obtained by purchasing textbooks for each module, which cost about £50.
Students have written to the university to complain about the charges, noting that the online assessments constituted between 10 and 20 per cent of the mark for each module.
University policy states that students must not be charged for sitting any exam for the first time.
A spokesman for the Exeter Business School said students had been paying for the tests for several years on the basis that the marks did not count towards their final module grades. This academic year, however, one lecturer had decided that the marks should count towards students' final scores.
The spokesman said the school was "entirely happy to accept that we got it wrong", and would be issuing refunds.
The tests are part of a variety of online materials supplied by publishers to accompany their textbooks, some of which require access codes, he said.
He added: "We have been very impressed by the richness of the materials, which exceed anything an individual lecturer could provide."