One of the biggest headaches facing eurozone authorities in the run-up to the introduction of euro notes and coins next January is the amount of money stashed outside the financial services system by the public.

While the Irish authorities may be looking for people to dig out their small change from the bottom of drawers to ensure there is enough coinage in circulation to keep commerce ticking over until the new currency arrives in our pockets, they have yet to address the problem taxing our partners in Europe.

Simply, they fear being overwhelmed by savings stashed in shoeboxes and the like which will have to be converted to the new currency.

In France alone, authorities reckon there might be as much as 150 billion francs hoarded - half the government's annual income tax revenues - and Germany too is worried about the scale of such unofficial savings. One of the problems - not unknown this side of the water - is that uncertainty surrounds the origins of much of this money.

The French are displaying their usual pragmatism in such matters. "We're not going to check back over five generations to find out where the money came from," said Finance Minister Laurent Fabius, emphasising that the logistics of the changeover were challenging enough without overwhelming the tax authorities. What will the attitude of our Revenue Commissioners be when such funds inevitably emerge from under the mattress here?

dcoyle@irish-times.ie