Taxes Consolidation Act 1997 section 77

Miscellaneous special rules for computation of income

Section 77 sets out special rules that modify how income tax law applies when calculating corporation tax, covering matters such as trade commencement and cessation, deductions for yearly interest and mineral rights expenses, the treatment of foreign trading income, relief for foreign tax on interest and royalties, and the taxation of non-resident companies with Irish branches.

• When a company begins or ceases a trade, it is treated as a new commencement or discontinuance for corporation tax purposes, even if the trade itself continues under different ownership.
• Yearly interest is deductible in computing trading income, and management expenses for mineral rights lettings in Ireland are also allowable, subject to the same restrictions as apply for income tax.
• Foreign income tax paid on overseas securities and possessions may be deducted, and where trading income includes foreign interest or royalties, the relevant foreign tax may reduce the chargeable amount — but not below zero, so no tax loss can be created.
• A non-resident company trading in Ireland through a branch or agency is chargeable to corporation tax on foreign income attributable to that branch, in the same way as a resident company would be.