Nearly a quarter of Brit don't know they have a download limit on their internet service, says Moneysupermarket.com.
According to the comparison website, of those web users that do know they have a download limit, 54 percent admitted they didn't know what their limit was.
Moneysupermarket.com warned that Brits using mobile broadband dongles without being aware of their download limits, could face huge charges of up to £200 for exceeding them.
James Parker, manager of mobiles and broadband said: "Dongle users are most at risk of incurring charges from exceeding download allowances as limits on dongles tend to be much lower than fixed line packages. Whilst the portability is great, users need to be aware that a dongles are most suitable for light users, fixed line is a better value option for heavy users".
"The most important thing is to know what type of user you are, dongles with higher limits are available for heavier users which can safeguard against exceeding the limit, but an unlimited fixed line package is the safer option for those planning to download a lot," he added.
Moneysupermarket.com also revealed that while a quarter of web users realised that limits stop heavy downloaders abusing the network, 30 percent said they thought download limits were unfair.
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