The Infrastructure Forum (Tif) has reported Microsoft to the Department of Trade and Industry (DTI) over its licensing changes which it believes will cost its members £880m over four years.
Furious Tif members said the price hikes should be investigated as a potential abuse of monopoly power. Tif has 98 corporate members with a combined IT budget of £18bn a year, including 22 of the UK's 50 biggest firms.
The group told the DTI that Microsoft's changes, which will be phased in from 1 October, will mean 94 per cent cost increases for their members.
David Roberts, chief executive of Tif, told vnunet.com: "Microsoft is using its dominant position to impose unfair prices. The changes are an unacceptable barrier to UK businesses' ongoing investment."
Microsoft is introducing a three-year subscription system whereby firms to pay a lump sum up front and then buy new software as it is released. The software giant has admitted that one in five of its customers will pay more following the changes, but claimed that the majority will be unaffected or pay less over time.
Tif said that all its members would end up paying between 10-225 per cent more.
Representatives from the group met with Microsoft executives earlier this month to discuss the changes.
Roberts said: "We presented our evidence to [Microsoft UK] and we think they were listening. Their public claims don't stack up with our evidence. All the responses from our members said they would see an increase."
Roberts said the DTI should look at investigating Microsoft's actions under the 1998 Competition Act.
"Our members have been loyal Microsoft customers for many years and they are furious. This new pricing policy is a slap in the face of every Microsoft customer."
Tif said that its members, which collectively have over 2.2 million desktop PCs and laptops and 52,000 Microsoft related servers, were now looking at how they could migrate away from Microsoft products. Some had already stopped new Microsoft projects, it said.
Analysts have said they have never seen so many users upset over planned licensing changes.
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