Work from home in NI for an ROI employer? You may be taxed in the wrong country

Remote and hybrid work made this arrangement completely normal. You live in Northern Ireland, your employer and your payslip are in the Republic, and you do the job from your own kitchen table. Nobody is commuting across the border. It feels like a detail nobody needs to worry about.

But the tax and social insurance rules were mostly written for people who cross the border to work, not people who never leave home at all. That gap is where a genuine trap sits: the wrong country's tax and social insurance can end up being deducted from your pay, by default, simply because nobody at the company checked.

What's the "remote worker tax trap" for cross-border employees?

It's when an employer keeps deducting tax, USC or PRSI (or UK tax and National Insurance) as if the employee worked in the employer's own country. In fact the employee works entirely from home in the other jurisdiction. The rules default to taxing income where the work is actually done, so the wrong country's deductions can be taken, sometimes for years, without anyone noticing.

It's easy to see how this happens. A Dublin-headquartered company hires someone who lives in Newry or Belfast and sets them up on the same payroll system as everyone else. Nobody flags that the new hire will never set foot in the Dublin office. Getting it right needs the employer to check actively.

Which country taxes your income if you live in NI and work remotely for an ROI company?

As a general principle under the tax rules between Ireland and the UK, employment income is taxed where the duties are physically carried out, not where the employer is registered. If your job is done from home in Northern Ireland, those duties are UK-based. So UK tax rules are generally what should apply to that income, even though an Irish company pays the salary.

On the Irish side, Revenue's own guidance for employers recognises this. Where an employee is non-resident in Ireland and does some or all of their duties outside the State, the employer can apply to Revenue for authorisation to stop deducting Irish tax and USC on the foreign-duty part of pay. Where none of the work is done in Ireland, it can apply for a full PAYE Exclusion Order.

Without that authorisation, the default is that the employer keeps deducting Irish tax and USC on the full salary, whether or not it's actually owed.

Do you pay Irish PRSI or UK National Insurance?

Social insurance generally follows where you actually do your work, not where your employer is. So working entirely from home in Northern Ireland normally means UK National Insurance applies, not Irish PRSI. If you genuinely split your time between an Irish office and home in NI, a separate "multi-state worker" rule applies. Broadly, if at least 25% of your working time or pay relates to your country of residence, that country stays responsible for your social insurance.

Either way, certainty comes from a Certificate of Coverage (also called a Portable Document A1) confirming which country is responsible. The Department of Social Protection issues it if Ireland is the competent state, and HMRC if the UK is. This prevents contributions being taken in both places, and protects the qualifying years that count toward your eventual State Pension in the correct country.

What if your ROI employer is already deducting Irish tax, USC and PRSI from your pay?

This is the trap in practice. It doesn't mean anyone did anything dishonest: running a remote worker through the standard payroll is simply the easy default, and it happens without the Revenue authorisation that would adjust it. The fix starts with a conversation. Ask your employer's payroll or HR team whether they've confirmed your tax and social insurance position with Revenue and HMRC, given that you work from home in the UK.

If Irish tax and PRSI have been wrongly deducted, there are routes to correct it. You can reclaim overpaid Irish tax and USC, and get a Certificate of Coverage to establish which country your social insurance should go to. But this can mean back-dated UK tax and National Insurance becoming due instead. It's worth having a cross-border tax adviser look at it rather than untangling it alone.

Does this work the other way — living in Ireland, employed by a UK company?

Yes — the same logic runs in reverse. If you're Irish-resident and working from home in Ireland for a UK-based employer, your employment duties are generally taxed in Ireland. The UK employer may need to register with Revenue to operate Irish payroll on your earnings, and any UK PAYE being deducted on those duties may need to stop.

The same 25% rule decides which country gets your social insurance if you're a hybrid worker splitting time between a UK office and home in Ireland.

UK employers with no presence in Ireland sometimes keep deducting UK tax and National Insurance by default too — for the same reason Irish employers do it the other way round. If this is your situation, the starting point is the same: confirm your residence and where your duties are actually performed, then check with Revenue and HMRC.

What should you actually do about it?

Common questions

This guide is general information, not tax advice. Cross-border payroll, tax residence and social insurance are genuinely complex and depend heavily on your circumstances. Always confirm your position with Revenue, HMRC and a qualified cross-border tax adviser before you act.

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