BT customers may find themselves tied to their broadband package for another year, even after their contract has expired, unless they notify the ISP immediately.
Under BT's rolling contract, which was introduced in April 2008, customers of the ISP will automatically be signed up for another year unless they inform BT that they no longer want the service.
If customers have been re-signed to the same package, they will be forced to pay up to £180 to extract themselves from the contract.
BT's renewal policy appears to be different to the majority of other ISPs, which do not automatically renew customers' contracts when they expire.
"We believe that rolling contracts are a sharp practice at any time, but particularly so in the current credit crunch and with given the riches available in the market," said Andrew Heaney from TalkTalk.
TalkTalk are also calling for Ofcom to stamp out the practice.
"BT cynically places the onus on its customers to cancel their contracts - simply because it knows that many of them will simply forget."
BT said the rolling contract only affects customers signed to the Option1 broadband package, which offered users free weekend calls on top of their broadband access. The ISP also says the renewable aspect is clearly stated in the contract.
"Customers make a clear positive choice to opt in to a renewable contract in exchange for the considerable benefit of free evening calls. Our customers are given clear information about the nature of their contract and what it means in exchange for the benefits they receive. The renewable aspect of the contract is clearly explained three times up front to the customer," said BT.
The ISP also revealed it contacts customers on the rolling contract 30 days before the expiry date reminding them it’s up for renewal.
"If they wish to leave at this point, they can without charge. Our communications are extremely clear on what the customer can expect, in return for the continuing benefit they will receive. Many other services, such as magazine subscriptions, insurance, car breakdown services are contracted in similar ways."
"Our approach is in stark contrast to some of our competitors, who will put you on a worse deal with no notice when your contract runs out," added BT.
Jessica McArdle, marketing manager of broadband comparison site Top 10 Broadband, said: "Top 10 Broadband is surprised by BT's decision to enforce rolling contracts on customers. Taking this approach is not particularly helpful to customers during these tough economic times. This policy is peculiar as other ISPs – including TalkTalk and PlusNet – are taking measures to reduce the cost of their broadband packages".