TAX officials are trawling through hundreds of thousands of credit card bills to find tax cheats.

The Revenue Commissioners have obtained details of 206,000 foreign credit cards and debit cards held by Irish residents, and tax officials are now poring through one million transactions to catch cheats secretly bringing undeclared income into the country.

The taxman wants to uncover people moving undeclared income back into Ireland from tax havens such as the Channel Islands, the Cayman Islands and eastern Europe.

The Revenue Commissioners obtained the data from two unidentified Irish banks following High Court orders, according to a Freedom of Information request made by the ‘Sunday Business Post’.

Countries such as Denmark, Australia, Sweden and the United States have already recouped millions from similar investigations.

The Revenue Commissioners has a special unit based in Dublin 15 to investigate tax fraud.

It is already a decade into an investigation of tax cheats, which has yielded €1bn for the Exchequer.

Money was stashed away in far-flung bank accounts during the boom and more cash was hidden from the taxman and the banks after the bust. Countries such as Romania and Bulgaria are popular destinations for hot money while Mauritius is also cropping up more often, the newspaper reported.

Investigations analysing vast amounts of data are increasingly common as computers become more sophisticated. Finance Minister Michael Noonan told the Dail earlier this year that Revenue is using social media websites such as Twitter and Facebook to scour for tax cheats.

Mr Noonan told the Finance Committee that tax officials were flushing out those involved in tax evasion or smuggling on the internet by using predictive analytics. “To detect those involved in tax evasion, the shadow economy and smuggling activities, Revenue uses big data and innovative technology, such as social network analysis and predictive analytics,” Mr Noonan said.

Scamming

Predictive analytics can detect patterns among tax cheats without doing time-intensive random searches. Computers have discovered that businesses that pay outstanding taxes in certain months or do business with certain countries are often involved in scamming.

A crackdown on social welfare frauds – also using big data – and the Revenue uncovered more than 900 scammers including one getting job seekers’ payments who had nearly €400,000 on deposit.

At least €9.5m was recovered by the joint venture called Operation Dirt. Minister Joan Burton said ‘big analytics’, allowed by investments in the department’s IT system, had found the tax cheats.