Three dates you will not want to miss with Revenue
Ireland’s tax system is often less complicated than people fear. On deadlines, though, Revenue has little sense of humour. Know these dates and you have the most important part of the paperwork under control.
No population register, but a registration
Ireland has no residents’ registration office where you record your address on arrival. What it has are two separate steps: the PPS number as your personal identification number, described in the section Arriving, and tax registration with Revenue.
Registration follows your role. Employees go through the PAYE system and the myAccount portal. If you are self-employed, have rental income or belong in self-assessment for other reasons, you register for income tax and use the Revenue Online Service, ROS for short. This registration is the moment your Irish tax life begins, and it belongs in the first weeks, not at the end of the year. We handle it as a service of its own: tax registration as a non-dom, together with the first tax return; if you want your whole arrival from a single source, you will also find it in the relocation package.
Who files a return
Self-assessment on Form 11 applies to everyone with significant income outside PAYE: the self-employed, landlords, shareholders receiving distributions, and practically every family for whom the remittance basis plays a part.
For newcomers, one point needs saying: even if the remittance basis means you pay little or no Irish tax, that does not automatically free you from filing. Remittances need to be declared, and the positions from the year of arrival, from the split year claim to the election to be resident, also go through the return. The details of the first year are on the page The year of arrival.
31 October and the ROS extension
The return for a year is due by 31 October of the following year. If you file and pay electronically through ROS, you get an extension of a little over two weeks each year; for the 2025 return it is 18 November 2026 (Revenue eBrief No. 034/26).
The extended date applies only if both the return and the payment go through ROS; otherwise 31 October stands.
| Step | Deadline |
|---|---|
| Form 11 return | 31 October of the following year |
| ROS extension for the 2025 return | 18 November 2026 |
| Preliminary tax for the current year | together with the return, 31 October |
| CGT payment for disposals between 1 January and 30 November | 15 December of the same year |
| CGT payment for disposals in December | 31 January of the following year |
The CGT payment deadlines run separately from the return; the details are on the capital gains tax page.
Source: Revenue on self-assessment (Pay and File); 2026 ROS date: Revenue eBrief No. 034/26; surcharges: Citizens Information, “Tax on income that is not from your employer”. As of: retrieved 25 August 2026.
Preliminary tax
31 October is a double deadline, and that is the quirk newcomers underestimate most. Together with the return for the past year, preliminary tax for the current year falls due: at least 90 per cent of the current year’s tax or 100 per cent of the previous year’s.
In the first full year of self-assessment, this means in practice that up to two years’ tax come together on one date: the balance for the previous year and preliminary tax for the current one. British readers know the principle from payments on account, which fall due on 31 January and 31 July; in Ireland it all lands on a single day. If you have not planned for it, your most unpleasant Irish tax moment comes not from a high rate but from cash flow.
The option of 100 per cent of the previous year’s tax is the predictable one: it is fixed as soon as the previous year has been assessed, and it protects you against estimating errors in the current year.
What lateness costs
A late return costs a surcharge on the year’s tax: 5 per cent if it is filed within two months of the deadline, 10 per cent after that. Late payments attract interest.
The surcharge is measured on the year’s tax, not on how late you are, and that is exactly what makes it sensitive for families with larger figures. Two months of dawdling can cost more than the fee for the whole return.
If you know Self Assessment from the UK, note two differences. The date: a British online return is due by 31 January after the end of the tax year, an Irish one by 31 October of the following year, and the ROS extension is the only one, under the condition above. And the penalty works differently: in the UK a late return first costs a fixed £100, in Ireland the surcharge is a share of the whole year’s tax.
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The first step is a conversation
Tax registration is part of what we take on for families moving to Ireland. Talk to us before the first deadline starts to run.