People who have notified the Revenue about undisclosed offshore income have less than a week left to make their disclosures online and to pay all tax, duties, interest and penalties owed in full.

Those using the NDO will take a 10% penalty if they disclose online and pay the full amount due, including the penalty by 12 March 2010.

To give those taking advantage of the New Disclosure Opportunity every chance of complying, the taxman is sending reminder letters out this week.

Once the scheme’s doors are closed, those found to have undisclosed offshore assets will be subject to full tax investigation, penalties of up to 100% and in the most serious cases criminal prosecution, HMRC warned.

Dave Hartnett, HMRC’s permanent secretary for tax said:

“Taxpayers with offshore investments who have notified us of their intention to disclose have done the right thing, saving themselves 90% of the potential penalties for failing to disclose.

"They now need to follow through by making their disclosure online and paying in full all the taxes they owe.”