Taxes Consolidation Act 1997 section 825A

Reduction in income tax for certain income earned outside the State

Section 825A provides income tax relief for individuals resident in the State who commute to work outside the State in a country with which Ireland has a double taxation agreement, commonly known as transborder workers relief.

• An individual holding a qualifying employment outside the State in a treaty country for a continuous period of at least 13 weeks, who has paid foreign tax on the employment income, may claim to have Irish tax reduced to the "specified amount" — effectively the tax attributable to non-employment Irish income only.
• The specified amount is calculated as A × B / C, where A is the Irish tax liability before credit for foreign tax, B is total income excluding qualifying employment income, and C is total income; where the relief is granted, no credit for foreign tax on the qualifying employment income is available.
• The relief does not apply to income taxed on the remittance basis, income subject to split-year treatment, income paid by a company to a proprietary director or spouse/civil partner, or income in respect of which the foreign earnings deduction or seafarer's allowance is claimed.
• The individual must perform the duties of the qualifying employment wholly outside the State (duties merely incidental to the foreign duties are treated as performed abroad), and must be present in the State for at least one day in each week during which he or she works abroad.