Electricians who have failed to pay the correct amount of tax have just one week to pay any tax owed and take advantage of more lenient payment terms from HMRC.
Under the Electricians Tax Safe Plan Campaign, HMRC is allowing electricians a 'window of opportunity' to come forward and settle any tax and interest they owe and receive a reduced penalty of 10 per cent.
Penalties of up to 100 per cent are usually charged for those who fail to disclose their tax bill, with a criminal investigation in the worst cases.
HMRC defines an electrician as anyone who installs, maintains and tests electrical systems equipment and appliances under stringent safety regulations, with the campaign covering any tax owed for whatever reason.
Electricians who have started working as self-employed, but have not told HMRC, are likely to have disclosed the incorrect amount of tax, it said.
Head of HMRC campaigns, Marian Wilson, is encouraging electricians to come forward to settle their tax affairs 'easily and on the best terms.'
"If you cannot afford to pay what you owe all at once, don't worry. Depending on your circumstances, you may be able to spread the payments," she said.
It is the second campaign HMRC has aimed at tradespeople, with the first targeting plumbers and heating engineers. Around £510 million has been collected so far from people coming forward through various campaigns - £120 million of this coming from follow up investigations.
Those intending to take part in the campaign must have informed HMRC by the 15 May 2012. However, HMRC states that it will still be beneficial for those to come forward as 'the penalty you pay will still be lower than it would be if HMRC comes to you first.'
Marian Wilson added: "Once the disclosure opportunity closes on 14 August, electricians who have not come forward but are found to have unpaid tax liabilities will face higher penalties, rising to 100 per cent of the tax evaded or, possibly, even criminal prosecution."