Dodgy tradies are being dragged through the courts as NSW Fair Trading clamps down hard on lying and unlicensed builders.

Six shifty tradies have been prosecuted this month, copping tens of thousands of dollars in fines, community service hours and intensive corrections orders between them, the authority says.

“No matter where it is operating in this state, Fair Trading investigators will track down unlawful activity in the residential building sector,” commissioner Rod Stowe said.

Mr Stowe said customers must be vigilant to stop building and renovation works going belly-up.

“Check your builder has a valid licence before any work over $5000 commences and always check that a valid insurance certificate has been obtained,” he said.

“For specialist work such as plumbing, electrical and gas fitting and refrigeration, check your tradesperson has the relevant qualifications.”