An estimated £87,000 has been paid out by Perth and Kinross residents to unsolicited traders and “shoddy” workmen over the past year.
The largest single payment made to any one individual stung by the traders was an eye-watering £10,000.
In the last year their dodgy activities have seen 50 people across the region make complaints to Perth and Kinross Council’s Trading Standards Team.
And a spokesperson for the team said: “We believe these figures to be only the tip of the iceberg as many victims of rogue traders are reluctant to report them.”
The ongoing problem has seen the council issue a fresh warning in a bid to prevent residents from being ripped-off.
There are particular concerns about one group of shoddy workmen known to be operating out of the Perth and Kinross area.
The firm whose services include the laying of driveways and patios is known to have repeatedly changed its name and telephone number in a bid to shake-off angry customers.
Trading Standards said they could not publicise the guises under which the businesses has operated for “legal reasons” and have instead asked homeowners to be extra careful.
A spokesperson said: “The firm canvasses door-to-door to promote its business and is known to have used various business names and telephone numbers.
“They change their name frequently, probably to distance themselves from complaints about previous or unfinished work.
“Trading Standards are advising people to be very wary about contracting with anyone who cold calls.
“Rogue traders can quite easily make themselves look legitimate by creating a website with what may appear to be genuine addresses, phone numbers and email addresses.
“Almost invariably these turn out to be false or untraceable.
“They are also known to ask for payments up front and then not to complete the work.”
Trading Standards recommends householders to get at least two quotes for the job in writing to compare what work is to be done and how much it will cost.
Community safety convener Councillor Douglas Pover added: “If you need work done on your house ask your friends, relatives or neighbours for personal recommendations rather than employing a cold caller.
“Perth and Kinross Council also operates the Better Business Partnership scheme where you can find a list of legitimate local businesses.
A list of members can be found on the council website at pkc.gov.uk or by phoning the call centre on 01738 476476.
In addition, anyone who has concerns about doorstep traders or any other consumer issues can contact Trading Standards via the Citizen’s Advice Consumer Helpline on 08454 04 05 06.