Under the HM Revenue & Customs’ so called Plumbers Tax Safe Plan relevant trades are being warned to contact the revenue before inspectors come knocking.

The letters warn that the spotlighted trades have until 31 May to declare earnings and pay the tax they owe.

Those making a full disclosure face a low penalty rate of 10% rising to a maximum of 20%. Once they come forward, they have until 31 August to make their disclosure and arrange for payment.

After that inspectors are vowing to pull together all available information to track down tradespeople that have not paid full tax, threatening big penalties and criminal prosecutions.

Over coming months HM Revenue and Customs inspectors will pick out various specialist trades where they think tax evasion is rife.

Mike Wells, HMRC’s Director of Risk and Intelligence, said: “We are using a variety of intelligence sources to target plumbers who have not declared their full income and I urge tradespeople in this group who think they owe tax on their income to get in touch with HMRC and get their tax affairs in order simply and on the best available terms.

“The first step for those wishing to avoid a full tax investigation with much higher penalties is to notify us.

“We do not think everyone who receives a letter owes us tax. However, if you owe tax and don’t get a letter, do not assume that HMRC will not catch up with you.”

Plumbers can call the HMRC special hotline on 0845 600 4507 or go to the website: www.hmrc.gov.uk/plumberstaxsafeplan