Ireland has a growing economy of people doing paid work outside their main employment — freelance design, consultancy, online business, trades work at evenings and weekends, content creation, coaching, rental income, and hundreds of other activities. Revenue has a word for this: trading income. And whether you think of yourself as running a business or just earning a bit extra, if you are receiving payment for goods or services on a recurring basis, you are a sole trader in the eyes of Irish law, with corresponding tax and compliance obligations.
The question of when — or whether — to move from sole trader to limited company is one I answer regularly for people who have started a side venture and found that it has grown to the point where the structure question is unavoidable. If you are at the very beginning, our complete guide to starting a business in Ireland covers the full registration and setup process.
Step One: Are You Already Declaring It?
Before we get to the incorporation question, the more pressing issue for some people is whether the side income is being declared at all. This is not a judgment — it is a practical observation. Many people who contact me about the tax position of their side business have been earning for one or two years without registering as self-employed or filing a tax return for the trading income.
If this is your situation, the answer is straightforward: register with Revenue as a self-employed person, file any outstanding income tax returns (you can go back up to four years with a voluntary disclosure), and declare the income. Revenue’s approach to voluntary disclosure is generally more lenient than audit-triggered discovery. The interest on underpaid tax will apply, but the penalties are generally lower.
The reason I flag this first is that some people assume incorporating will somehow solve the undeclared income issue — that forming a company creates a clean break. It doesn’t. The prior trading income, if undeclared, remains your personal tax liability regardless of any subsequent company structure.
The Tax Tipping Point for Incorporation
As a sole trader, all your trading profit — from your side business and your main employment — is combined as personal income and taxed at your marginal rate. If you are a PAYE employee already using your standard rate band (earning more than approximately €44,000 per year from your job), your side business income is taxed from the first euro at the higher rate: 40% income tax, 4% PRSI, 8% USC for income above €70,044 — approximately 52% in total on each euro of side business profit.
That is a high marginal rate, and it applies even if your side business is generating relatively modest income — €5,000 to €10,000 per year.
However, the point at which incorporating saves you enough tax to outweigh the compliance costs of running a company is higher than many people expect. A rough guide:
If your side business is generating less than €20,000 net profit per year, and you are drawing all of it personally, incorporation is unlikely to save you money after accounting for the additional accountancy and CRO compliance costs (typically €1,500–€3,000 per year more than sole trader compliance).
If your side business is generating €30,000–€50,000 or more per year, and — crucially — you do not need to withdraw all of that profit personally, incorporation starts to make financial sense. The profit retained in the company is taxed at 12.5% rather than your personal marginal rate of up to 52%. The tax saving on retained profit is real and compounds over time.
The key phrase is “do not need to withdraw.” If you need all the money to live on, there is no retained profit advantage — you pay personal tax on it when you take it out anyway.
The Liability Question for a Side Business
Alongside the tax question, there is a liability question. If your side business carries any risk of a claim against you — a client dispute, a professional negligence claim, a personal injury on a premises you control — operating as a limited company means that (in most circumstances) your personal assets are not exposed to that claim.
For a trades-based side business — fitting kitchens, doing electrical work, building extensions — the liability exposure is real. A limited company does not eliminate the need for public liability insurance, but it does provide a legal separation between the business’s liabilities and your personal finances, including your family home.
This liability consideration is often more relevant to the timing of incorporation than the pure tax calculation, particularly for side businesses in sectors where personal injury or professional indemnity claims are a realistic risk.
What Changes Practically When You Incorporate
When you incorporate a side business, several things change:
You need a separate company bank account. The company’s money is not your money. Mixing company and personal funds is a breach of your duties as a director and one of the most common financial mistakes new business owners make.
You need to run payroll if you pay yourself a salary. Any salary drawn from the company must go through PAYE, with Revenue notified in real time under PAYE Modernisation.
You need to file annual company accounts and a CRO return. This is the main compliance overhead — accounting costs rise, and there is a fixed annual CRO filing requirement.
The company pays corporation tax, not income tax. You personally pay income tax only on money you actually extract from the company.
You are now a company director with the legal duties that carries — including the obligation to ensure the company’s affairs are properly managed and its statutory filings are made on time.
The Hybrid Phase: Running Both
One common pattern I see is a transition period where someone runs both a sole trader activity and a limited company simultaneously — perhaps because some work is contracted directly to them personally (existing client relationships), while new work is contracted through the company. This is legally permissible but requires careful accounting to keep the two income streams separate and to ensure there is no artificial shifting of income between structures.
For most people, the cleaner approach is to move all business activity into the new company once it is formed, and to wind down or transition the sole trader activity within a defined period.
When Is the Right Time?
The right time to incorporate is when at least one of the following is true:
Your net side business profit consistently exceeds €30,000–€40,000 and you do not need to draw all of it each year. Your sector carries meaningful personal liability risk and you want the protection of limited liability. A key client or contract requires you to have a company structure. You are planning to grow the side business into a primary business and need a scalable structure. You want to make pension contributions through the company (which can be very tax-efficient from the outset).
It is not the right time if your profit is low, your clients don’t require a company, and you need to draw everything you earn personally. In that situation, the compliance overhead of a company costs more than it saves.
If you are at a point where you are genuinely uncertain — if the numbers are in the range where it could go either way — book a conversation with an accountant and model it properly for your specific situation. The answer will be clear once the numbers are in front of you. For more on this and related decisions, browse our business startup guides.
Paddy Malone FCA AITI
Paddy is the principal of Malone & Co. Chartered Accountants in Dundalk. A Fellow of Chartered Accountants Ireland and a Chartered Tax Consultant with the Irish Tax Institute, he has been advising businesses across County Louth and the North-East for over 35 years.