Tax cheats get little sympathy. As a result, the Revenue Commission's belated drive to uncover a culture of evasion in the Republic between the 1970s and the 1990s has received at least tacit support.

Most people have not been in the position of having substantial funds to salt away in foreign accounts and the majority were never put wise to the attractions of bogus non-resident accounts. Life policies, however, are a different matter.

The Revenue's current campaign to track down hot money that was paid into single-premium insurance products over the past 20 years has set off alarm bells in households around the State - especially among the elderly.

Life assurance companies, with the notable exception of Irish Life & Permanent, have written to every customer who invested a lump sum of €20,000 or more in such a policy since 1980. And the deadline for those with issues to address is Monday.

The arrival of the letters has been an unwelcome shock to thousands of people around the State who have invested perfectly legitimate funds in such policies.

Many, especially those who invested in the early 1980s and are now quite elderly, assume that any notification of a Revenue investigation means that they are the subject of such an inquiry.

Frank Hussey, president of the Irish Taxation Institute (ITI), says that the rushed nature of this campaign and the confusing information programme that has accompanied it have left many people extremely confused about its scope.

ITI chief executive Mark Redmond notes that it appears to be largely the most compliant taxpayers who have been intimidated by this current campaign.

So what is the situation? What rights do individual investors have and, if the revenue does pursue them, how do they go about presenting their case?

The most important thing to note is that receipt of the letter in itself means nothing - the only parameter in determining who did and who didn't get such a letter was that they had, at some point, invested above the threshold of €20,000 in one of these perfectly legitimate insurance products. The fact you have a letter doesn't mean that you are in trouble.

"The receipt of one of these letters is not, of itself, an indication that the recipient has tax problems," says Mr Hussey. "It would appear that a great number of these letters have been received by compliant taxpayers."

So, are such customers going to have to prove they have nothing to hide?

Absolutely not, according to Mr Hussey. "To quote from Revenue's own website: 'Proof is not required and no notice of intention or disclosure is required to be submitted'," he says.

The ITI has meet Revenue chairman Frank Daly to emphasise the importance of this statement to compliant taxpayers, especially in the next phase of the campaign.

Mr Hussey also pointed out that the Revenue's charter includes an important statement by the Revenue that it will assume that a taxpayer has been honest in their dealings with the Revenue unless there is a clear reason to believe otherwise.

The fact that you might not have records of your investment, equally, should not give cause for concern, according to the institute. It notes that taxpayers are under no obligation to retain records for 15 or 20 years. In fact, business taxpayers are required to retain records for only six years.

"Typically, even Revenue doesn't hold records on taxpayers for such a lengthy period," says Mr Hussey. "It can also be assumed that many of the life assurance companies will have great difficulty in sourcing documentation over this timeframe."

In fact, a number of insurance companies have set up helplines dedicated to helping customers who have received letters in relation to the Revenue investigation. These include Irish Life & Permanent, which refused to accommodate Revenue in sending out the letters to customers in the first place.

If you're not sure whether you do or don't have a liability, you can make a "protective" notice of intention to disclose - sending Revenue the one-page form downloadable from its website by the Monday deadline. This allows you a further two months to try to determine your position.

It is worth remembering that 20, or even 15 years, ago, the equivalent of €20,000 was a relatively substantial sum - not one that was likely to totally slip the mind or be record-free.

As to people who worry that they might have some smaller untaxed sum invested in such policies but have received no letter, the best advice is to get the tax issue sorted out as soon as possible. The current campaign is targeted at funds in excess of €20,000, so you are not facing a Monday deadline, but you still have a tax problem and the Revenue can investigate at any time.