Some 19,260 audits by the Revenue Commissioners in 1998 identified tax underpayments of £160 million, the annual report shows. Audit programmes involved checks on the tax affairs of the self-employed and companies.

Of the £160 million identified, some £157 million has been paid with the balance due to be received in future years. The number of audits in 1998 was fewer than the 20,786 in 1997 but the tax yield exceeded the £154 million generated in 1997.

The Revenue strategy was to take "a stronger stance" against non-compliance and against "phoenix syndrome" companies, said Revenue chairman, Mr Dermot Quigley. Full statutory interest as well as penalties would be charged. Because the Revenue was now surer of taxpayers' liability, they were charging the full interest liability, Mr Quigley said.

Interest charges of £19 million were collected in 1998, up 17 per cent on the previous year. The Revenue has set out a "Code of Practice for Revenue Auditors" to reflect the stronger stance being taken against non-compliance. This also sets out the range of offences considered for prosecution.

The largest number of audits - 9,162 - concerned VAT payment and identified underpayments of a little more than £45 million. The Revenue challenged tax-avoidance measures in 16 cases and generated payments of £2.9 million. Of the 304 customs audits, 34 per cent showed no irregularities, 40 per cent led to payments of £1.7 million, 12 per cent led to repayments by the Revenue of duty overpayments of £0.7 million and 14 per cent showed non-monetary discrepancies.