I assume that the Deputy is referring to any outstanding contributions that may be owing with respect to an individual’s membership of a public service Spouses' and Children’s Contributory Pension Scheme, which I understand are deducted from the pension lump sum at point of retirement.
My information is that individuals should qualify for tax relief in respect of such 'abatement' in accordance with the normal provisions applying to pension contributions under the tax code. However, it is a matter for the individual to liaise with the relevant Tax Office in order to recoup any tax refunds due to them, and I understand that the pension administrator will normally provide the relevant documentation to enable this to be done.