I separated from my wife about two years ago.

Before we separated, we were jointly assessed as a married couple for tax purposes.  At the time, my wife and I were both self-employed and working for different companies.

When we separated, she left Irelandand now lives in Britain.  I recently received a letter from the Revenue Commissioners advising me that my former wife underpaid tax while she was self-employed and advising me to repay this tax, along with penalty interest.

Am I liable for this tax bill and if so, why?

My wife ifs no longer living in Irelandand I do not have any contact details for her.

This is an unusual case where the result seems unfair to the taxpayer.  A similar point was addressed in a tax case in the High Court some years ago involving Mrs. Gilligan (the wife of John Gilligan, who was being pursued by the authorities for tax liabilities in circumstances where she was jointly assessed with her husband.

However, strangely, the tax law is different when the husband is being pursued for his wife's tax liabilities.

Where a married couple are jointly assessed to tax, the husband is the chargeable person.  As such, he is liable for both his own and his wife's tax liability.  There is no doubt an anachronism in the law which originates from long ago when tax laws were drafted assuming that the husband was the breadwinner.

In theory, the Revenue seems to be within its rights in pursuing the husband for arrears of his wife's tax for the years of assessment for which they were jointly assessed and during which they were both resident for tax purposes in Ireland.

This seems unfair - but no doubt the Revenue would argue that, by accepting joint assessment, the husband was accepting the obligation to pay his wife's tax.

There may be some helpful points to raise as follows:

Ø      Joint assessment can only have effect for any year of assessment in which both spouses are Irish resident.  Therefore, for any period since the wife moved to Britain, he cannot be assessed on her income.

Ø      Penalty interest can only be levied in cases of fraud or neglect

It is arguable that a case can be made to Revenue (or the courts, in the case of disagreement) that the husband has not been guilty of any fraud or neglect in not dealing with outstanding liabilities of his estranged wife when he could not have actually been aware of her personal financial circumstances.

To be sure of this point, it would be necessary to know how much the husband knew - or could have known- about his wife's tax affairs.

Ø      If there is no fraud or neglect by the husband, there is an argument that any assessments raised more than four years after the filing date of the relevant tax return are not valid.

This four-year rule is to give taxpayers some closure for years long past.

The Revenue could claim that, by agreeing to be jointly assessed with his wife, the husband assumed responsibility for ensuring that her tax affairs (as well as his own) were properly handled.

However, the husband may be able to make the case that he could not reasonably have been expected to be aware of the relevant details of his wife's tax affairs.

Ø      As a general point, it would seem wise before finalising any separation arrangement to scrutinise the parties' tax affairs and verify outstanding taxes, particularly where join assessment has applied up to the time of separation.

Appropriate adjustments could then be made in respect of matrimonial property.

Michael Gaffney is a director of KPMG.