Eleven financial management businesses have been targeted. They run websites which imply they are affiliated with organisations such as the Consumer Credit Counselling Service or Citizens Advice, by using similar domain names and copying some of the legitimate sites' content.
The OFT, which has received complaints from a number of genuine debt advice charities, is warning consumers to be vigilant. The offending sites often charge for advice despite the websites they ape supplying free information.
The guilty companies have been ordered to stop using the trading names with immediate effect. Those without a licence to operate at all have been told to stop trading or face prosecution.
Businesses that offer credit or lend money, including those that provide advice on debt, must be licensed by the OFT and must notify the OFT of all trading names they intend to use.
Internet service providers have been called in to help ensure the websites are removed from the public domain promptly.
Ray Watson, director for consumer credit at the OFT, said the organisation would take action against businesses that use look-alike websites to mislead customers.
Watson said: "Consumers are also reminded that they should not deal with any company that does not have a consumer credit licence.
"These unlicensed businesses are unregulated and consumers may have no means of redress if things go wrong."