🇮🇪 COUNTRY A Ireland VS 🇬🇧 COUNTRY B UK

UK wins significantly. In Ireland, €80,000 pays roughly €28,000 in combined tax (income tax + 8% USC + 4% PRSI). In UK, £68,000 (equivalent) pays about £18,000 (income tax + NI). That's ~€10,000 more take-home in the UK. Ireland's 40% bracket starting at just €42,000 is the culprit.

Universal Social Charge (USC) is Ireland's additional tax on gross income: 0.5% on first €12,012, 2% up to €27,382, 4% up to €70,044, and 8% above that (2025 rates — verify Budget 2026 adjustments). Unlike income tax, USC applies from euro one with no credits or allowances. On €80,000 income, expect ~€4,400 in USC alone. UK has no equivalent surcharge.

Between £100,000-£125,140, UK taxpayers lose £1 of personal allowance for every £2 earned. This means you pay 40% tax PLUS effectively lose £12,570 of tax-free income. The marginal rate hits 60% in this band. Ireland has no equivalent trap—its rates are straightforward, just higher overall.

Ireland—especially Dublin. Google, Meta, Apple, Microsoft, and most US tech giants have EMEA HQs there. Salaries are competitive (€100K+ for senior engineers), and Ireland's 12.5% corporate tax makes stock options more favorable. UK has good tech jobs too, but post-Brexit, fewer companies use London as EU base.