East Sussex Trading Standards issued the warning after receiving several complaints of rogue doorstep sellers operating in the Bexhill and Lewes areas.
Officers are particularly keen to intercept a cold calling company offering block paving to residents, whose methods have aroused suspicion.
Cllr Rupert Simmons, East Sussex County Council lead member for economy, said: “Cold callers can be very persuasive and may end up talking people into work they don’t really need.
“People should not allow themselves to be pressured into agreeing for work to be carried out straight away, even if the price quoted appears attractive.
“It’s far better for people to take their time, do the research and ensure they know who they’re dealing with and are paying a reasonable price for a good job of work.
“If anyone is visited by a cold caller and is suspicious about their practices, we’d urge them to report it, to help us tackle this problem and prevent people from becoming victims.”
In the past Trading Standards has successfully prosecuted rogue traders for offences including over-charging, carrying out unnecessary work, providing poor quality goods, materials or services.
People are advised not to deal with people who knock on the door offering home improvement work and to be particularly wary of callers who claim they are ‘only in the area today’.
Anyone who agrees to work costing more than £42 has a legal right to a 14-day cooling off period in which to cancel their agreement.
Anyone who has information about a suspicious cold caller is asked to call the Citizens Advice Consumer Service on 03454 040506.
People who want to deter cold callers can obtain a free ‘super sticker’ which they can display at their front door warning doorstep traders to stay away, which is available by calling the same number.