Mr. Shay Cody:

There are a couple of reasons. First, certain casual low-paid workers are not in the tax net at all.

There is no point claiming something from which one will not benefit.

Second, it is somewhat similar to tax relief on medical expenses. There can be a lot of work involved in making a tax relief claim and if the amount of money involved is relatively modest, people sometimes do not get around to it. The Revenue estimates that only 50% to 60% of people claim their medical expenses. People are less likely to do so if the sums involved are not very high. There will always be some dead weight regarding tax expenditure and in this case that is the difference between the actual cost of €26 million and the estimated cost of €39 million. I am unsure it would ever cost €39 million because some union members do not pay tax, either because they were not in employment for the full year or have very low earnings which are, therefore, non-taxable.