The dealings between the Revenue Commissioners and more highly paid professionals have always been a bit opaque. Those in the PAYE system are, like all PAYE employees, caught before they even see their pay packets. Indeed, all the data shows that a group of more highly paid people pay a very significant amount of tax. Those in households with earnings above €100,000 pay more than half of all income tax, according to Revenue.

However, for many years there have also been stories of tax schemes used by highly paid professionals to avoid tax. In most cases these were legal devices resulting from property tax incentives, many of which have been gradually phased out.

Meanwhile, the opportunities for evasion have always been greater for those outside the PAYE system, as they had more opportunity to hide their earnings. And remember those old building society ads which coyly promised “ confidentiality”?

The system has tightened up in recent years, certainly for those who are tax residents. Those who aren’t can continue to run their affairs, like the big multinational companies, by basing themselves in low-tax countries.

The latest soundings from Revenue, as we report today, are that it is once again going to take a harder look at the “white collar” taxpayers, and particularly at higher earning professionals, many of them outside the PAYE system.

For years Revenue has pursued the loopholes established by the tax industry here, persuading successive ministers to close off the more egregious ones. The latest actions suggests that Revenue believes there is more work to be done, both in closing off more loopholes, as well as delving into grey areas, such as where somebody operates as a “consultant” but is effectively an employee.

And Revenue’s firepower is growing. Not only does it now have much more access to Irish information, such as payments made to state bodies, but it is in receipts of much more international information under tax cooperation agreements. Indeed, the word is that Revenue has begun to receive significant information from a 2014 agreement on information sharing among other revenue authorities. This could yet get interesting.