Schools across St Helens pay £100,000 over the odds for expensive phone tariffs every year, according to new research.
The survey claims pressurised headteachers and governors are not getting the best deals from telecoms firms.
Research by Equinox, an independent telecoms broker, suggests most schools do not check they are getting the cheapest rates possible.
David Millett, the report’s main author, said few schools have the procurement know-how to barter for bargains.
“With most councils having devolved telephony procurement to the schools, it is unsurprising,” he said. “Let’s face it, the telephone companies aren’t in the business of informing people when they could get cheaper rates.”
He also cited increases in calls to mobiles as a major factor for higher bills.
“Phone bills for schools have crept up over the last few years,” added Mr Millett. “Not because they are making more calls or the rates have increased; it’s simply because of the patterns of calls being made.
“Schools are required to have contact numbers for every pupil. You go back 10 years and the majority of those numbers would have been landlines, with the occasional office number thrown in.
“Over time the mix of numbers has migrated from landlines to mobiles. We’ve all got a smartphone and many of us only really have a landline because we need it for our home internet connection.
“We make far more calls on our mobiles and we expect more people to call us on them.”
A spokesman for St Helens Council declined to comment.