Self-assessment
Most sole traders, landlords and PAYE workers with side income can do this themselves. You are not calculating the tax — ROS does that. You are gathering figures, putting them in the right boxes and checking what comes back.
The work is in the paperwork, not the arithmetic. Once the figures exist, filing takes hours rather than weeks — and the return for the 2025 tax year is due by 31 October 2026, or 18 November 2026 if you both file and pay through ROS.
Filing your own return is a reasonable default, not a rule. These are the cases where an accountant earns the fee, and no amount of software changes that.
Registering as an employer, operating PAYE in real time and getting the first payroll submissions right is a separate job from your income tax return, with its own deadlines and its own penalties. The return is the easy half.
The moment correspondence stops being routine, you are negotiating rather than filing. Someone who has done it before is worth what they charge, and the cost of getting it wrong is not capped at their fee.
A limited company means corporation tax, statutory accounts, a CRO filing deadline that will strike off your company if missed, and directors' returns on top. Different regime, different return, different consequences.
Matching rules decide which shares you are treated as selling, and the answer changes the gain. Employee share schemes, dividend reinvestment and repeated small purchases are the ones that get it wrong quietly.
Foreign rental income, foreign employment, offshore funds, non-residence or split-year treatment. Double taxation relief and the reporting rules that come with offshore products are the deep end, and some of them force you into mandatory electronic filing regardless.
If none of those describe you — a sole trade with no employees, a property or two, a PAYE job with income on the side — the return is within reach of anyone willing to be organised about receipts.
Three steps, in this order. Only the first one takes real time.
Every invoice you issued, every receipt you paid, and the bank statements that prove both. This is the part people underestimate, and it is the part that decides whether the rest takes an afternoon or a fortnight.
Sort the spending into the headings the Form 11 asks for, and put the private share of anything mixed — car, phone, home — on the private side of the line. Getting this honest at the start is what makes the figures defensible later.
Open the return, work down the panels, enter the totals. ROS calculates the liability, applies your credits and shows you the result before you sign. If the figures are ready, this is an evening.
Not always, though in practice nearly everyone starting out today does. Mandatory electronic filing does not apply to every chargeable person by default — it applies to named categories, including anyone filing a Form 46G, anyone subject to the high earners' restriction, anyone with foreign life policies, offshore funds or other offshore products, and anyone claiming certain property-based incentives. Separately, every self-assessed taxpayer who registered or re-registered from 1 January 2015 onwards must file and pay electronically. Paper filing still exists for older registrations outside those categories, and a paper return loses the ROS deadline extension.
All three are honest mistakes, and all three overstate your expenses — which is the direction that costs you if the return is ever looked at.
No. Revenue lists LPT explicitly among the expenses you cannot deduct from rental income. It reads like a property cost, it is paid on the property, and it is still not allowable. The same list rules out pre-letting expenses and any charge for your own labour on repairs.
Expenses you cannot deduct from rentNot as a deduction. Money you take out of a sole trade is drawings, not a business expense — it is your profit, already taxed as profit. There is no salary line for the owner of a sole trade, and putting one in understates the profit the return is built on.
What counts as a business expenseUsually not. A meal bought while working away is not automatically deductible. Subsistence has conditions about distance, duration and whether the trip is genuinely outside your normal pattern of work, and an ordinary day trip usually fails them.
Subsistence rulesIn the order you will need them.
31 October 2026, or 18 November 2026 on ROS — and what happens if you miss them.
OpenEverything to gather before you open the return, so you only sit down once.
OpenIncome and expenses for the year, totalling into the headings the Form 11 asks for.
OpenRental income and expenses per property, on the rules that apply to rent.
OpenGeneral information about filing your own return, not tax advice. Sources are Revenue's Tax and Duty Manual Part 41-00-28 (A Guide to Self Assessment, section 5.2 on the mandatory requirement to file electronically, giving effect to S.I. No. 223 of 2011 and S.I. No. 572 of 2014), Revenue eBrief No. 034/26 for the 18 November 2026 ROS pay and file date, and Revenue's published list of expenses that are not allowed against Irish rental income. Rules and thresholds are revised; confirm on revenue.ie before you file.