Police are 'urgently' investigating a rise in reports of elderly islanders being targeted by traders operating illegally.
The force has issued a warning, saying traders operating without the necessary permits are knocking on doors and offering roofing, power washing, cleaning and other handyman jobs.
They're travelling around the island in UK-registered vans, and a post on the States of Jersey Police Facebook page lists some of the company names they are working under.
The force has launched a joint investigation with the government's Population Office.
They want anyone who has paid for their services to report it by calling the police or emailing hello@jersey.police.je, quoting: 13/09/23/610.
"Some people might be embarrassed about the large sums of money given to these companies, but we want to help and support you."
Islanders are asked to check with older relatives that they have seen the message and haven't been affected.

'Partnership Leads' appointed of new school grouping system
Businesses to get more money towards cost of training staff
Andium marks record year for new homes in Jersey
Princess Anne opens Jersey Zoo gorilla enclosure
Tarifa Jet and Caesarea Trader return to service
Jersey Post returns to profit
Could harnessing the youth vote change the election?
Inclusive island-wide fundraising challenge asks for 'moment of understanding'