Small Business Tax in Ireland

Irish small-business entity structures

Ireland offers a range of small-business operating structures, each with distinct tax and compliance characteristics:

• Sole trader (Schedule D Case I or II): A single individual operating a trade (Case I) or profession (Case II) under personal income tax. See the Ireland self-employed tax crossover for sole-trader analysis.
• Partnership: Two or more persons under the Partnership Act 1890. Tax-transparent — the partnership lodges a Form 1 (Partnership) return; partners report shares on their personal Form 11.
• Limited liability partnership (LLP): Available since the Investment Limited Partnerships Act 2020 amendments. Tax-transparent like a traditional partnership.
• Limited company (private company limited by shares — LTD): The dominant Irish small-business structure since the Companies Act 2014 reform. Single-document constitution, simplified registration, minimum one director (must be EEA-resident or company hold a Section 137 bond), one shareholder, EUR 1 minimum issued capital. Taxed under the corporation tax regime.
• Designated Activity Company (DAC): Successor to the pre-2014 private limited company. Retains the memorandum-and-articles model and objects clause. Less common than LTD; used where specific activity restriction matters.
• Unlimited company (ULC): No limited liability. Used for specific commercial reasons (typically privacy of accounts under the old framework, though disclosure requirements have tightened).

The Companies Act 2014 consolidation made LTD formation simple and low-cost. Online incorporation via the Companies Registration Office (CRO) costs EUR 50 and typically completes within 5 working days.

Irish corporation tax rates

The three principal Irish corporation tax rates under TCA 1997:

• 12.5% trading rate — applies to Schedule D Case I/II trading profits. One of the lowest corporation tax rates in the OECD, sustained since 2003. The trading rate is the cornerstone of Irish industrial policy and has been a magnet for foreign direct investment.
• 25% non-trading rate — applies to passive income (rental from non-trade property, foreign dividends not derived from active trade, interest, royalties from non-trade IP). The 25% rate is materially higher than the 12.5% trading rate, creating a structural incentive to characterise income as trading where commercially supportable.
• 33% capital gains rate — applies to chargeable gains on disposal of assets, matching the individual CGT rate. The 33% rate is among the higher CGT rates in Europe.

The trading vs non-trading distinction is the principal substantive question for Irish small businesses. Trading income requires:

• A regular pattern of business activity with a profit motive.
• Substance: meaningful operations, employees, decision-making in Ireland.
• Linkage to a clearly identifiable business or trade.

The trading-or-not question has substantial case law (Cape Brandy Syndicate, Marson v Morton, Iswera) and Revenue guidance. The badges of trade test considers profit motive, number of transactions, length of ownership, supplementary work, circumstances of sale, and source of finance.

OECD Pillar Two and the QDMTT

From 31 December 2023, Ireland implemented the OECD Pillar Two framework through the Finance (No. 2) Act 2023, embedding a 15% effective minimum tax for in-scope multinational enterprise (MNE) groups:

• Scope: MNE groups with consolidated revenue of EUR 750 million or more in at least 2 of the prior 4 fiscal years.
• Qualified Domestic Minimum Top-up Tax (QDMTT): Ireland's domestic implementation imposes a top-up tax to ensure in-scope Irish entities of MNE groups pay at least 15% effective tax. The QDMTT applies first, preserving Irish taxing rights over Irish-located activities.
• Income Inclusion Rule (IIR): Ireland applies the IIR to Irish parent companies of low-taxed foreign subsidiaries — imposing top-up tax on the Irish parent for foreign-source income taxed below 15%.
• Undertaxed Profits Rule (UTPR): Effective in Ireland from 31 December 2024 for fiscal years starting on or after that date — the backstop where neither QDMTT nor IIR have applied.

Material point for SMEs: The Pillar Two framework applies ONLY to in-scope MNE groups (EUR 750 million+ consolidated revenue). Genuine Irish SMEs continue to operate at the 12.5% trading rate without any Pillar Two impact. The 12.5% rate remains the headline rate for the Irish economy.

For in-scope MNEs, the 15% effective rate is calculated under GloBE rules — a separate calculation parallel to local corporation tax computation, with specific adjustments and timing differences.

Start-Up Relief — Section 486C TCA 1997

Start-Up Relief under Section 486C TCA 1997 provides up to EUR 40,000 corporation tax relief per year for the first 3 trading years of a new Irish company:

• Eligibility: New companies starting a new trade in Ireland. Must NOT be a successor to an existing trade carried on by another entity (anti-recycling rule). Must be genuinely commencing trade.
• Relief calculation: The relief is the LESSER of: (a) EUR 40,000 corporation tax (effectively shielding EUR 320,000 of trading profit at 12.5%), and (b) the employer's PRSI Class A contributions paid in the year (subject to a maximum EUR 5,000 per employee).
• Three-year window: Years 1, 2, and 3 of trading. Unused relief in any year can be carried forward (subject to specific carry-forward rules).
• Connected entity exclusion: Companies controlled by individuals who already control significant trading interests in Ireland may be excluded — anti-fragmentation rule.

Start-Up Relief was originally a 3-year sunset relief from 2009 but has been progressively extended. Finance Act 2024 extended Section 486C through 2026. The relief is materially valuable for genuine new SME starts, particularly those with payroll above EUR 40,000 (where the employer PRSI cap binds at a productive level).

R&D Tax Credit — Section 766 TCA 1997

The Research and Development (R&D) Tax Credit under Section 766 TCA 1997 provides a 30% credit on qualifying R&D expenditure (raised from 25% in Budget 2024, effective for accounting periods commencing on or after 1 January 2024):

• Qualifying expenditure: Wages and salaries of R&D personnel, materials consumed in R&D, qualifying overheads, subcontracted R&D (subject to caps), R&D facility construction costs.
• Refundable element: The credit is fully refundable in three annual instalments — material for loss-making startups without a corporation tax liability to absorb the credit.
• Stand-alone application: The R&D Tax Credit can be claimed alongside the standard deduction for R&D costs, doubling the effective benefit. A EUR 100,000 qualifying R&D spend yields a EUR 12,500 trading-profit deduction (at 12.5%) PLUS a EUR 30,000 refundable tax credit.
• Claim deadline: Within 12 months of the end of the accounting period.
• Definition of R&D: Must satisfy the systematic, investigative, or experimental test — seeking to achieve scientific or technological advancement with appreciable scientific or technological uncertainty.

The Irish R&D Tax Credit is materially more generous than equivalent regimes in most OECD countries — the combination of high credit rate (30%), refundability, and Ireland's 12.5% headline trading rate makes Ireland a competitive location for R&D-intensive SMEs.

Knowledge Development Box (KDB)

The Knowledge Development Box under Part 29 Chapter 5 TCA 1997 provides an effective 6.25% corporation tax rate (half the 12.5% standard rate) on qualifying income from R&D-derived intellectual property:

• Qualifying income: Royalties and other income from qualifying assets (patents, copyrighted software, plant breeders' rights, supplementary protection certificates) developed through R&D conducted in Ireland.
• Modified nexus approach: Implementation follows the OECD BEPS Action 5 modified nexus approach — only the income proportionate to R&D conducted within the qualifying entity (with limited outsourcing) qualifies for the reduced rate.
• Mechanism: Specified percentage of qualifying profit is taxed at 12.5% with the remainder taxed at the KDB effective rate of 6.25%.

KDB was available since 2016 (the first patent-box-style regime fully aligned with BEPS Action 5 modified nexus). It is less impactful than initially anticipated due to:

• The modified nexus requirement excluding R&D outsourcing.
• Substantial documentation requirements for qualifying-income computation.
• Pillar Two interactions for in-scope MNEs (KDB benefit may be partially eroded by Pillar Two top-up calculations).

Annual compliance and reporting

Irish companies face two principal annual filings:

• Form CT1 corporation tax return: Due 9 months and 21 days after the accounting period end (extended to mid-November via ROS for companies aligned with calendar year). Self-assessment regime — Revenue does not issue an assessment.
• Annual Return and Financial Statements to CRO: Annual Return Date (ARD) typically 6 months after the company's accounting year-end. Financial statements attached. Late filing triggers EUR 100 fixed penalty + EUR 3 per day late + loss of audit exemption status.

Preliminary Corporation Tax payments under Section 959AS TCA 1997:

• Small companies (corporation tax under EUR 200,000 in prior year): Single instalment of 100% of prior-year tax or 90% of current-year, due 31 days before the accounting period end.
• Large companies (corporation tax EUR 200,000+ in prior year): Two instalments — first instalment 6 months and 21 days into the accounting period (45% of prior year or 50% of current year), final instalment 31 days before period end (top up to 90% of current year).

Audit exemption under Sections 358-365 Companies Act 2014 applies to companies meeting two of: balance sheet total under EUR 6 million, turnover under EUR 12 million, employees under 50. Audit exemption may be lost for late filing of annual returns — the most common reason small companies face mandatory audit.

Employment and Investment Incentive (EII)

The Employment and Investment Incentive under Part 16 TCA 1997 provides income tax relief for individuals subscribing for shares in qualifying Irish SMEs:

• Relief rate: 40% of qualifying investment, available immediately (front-loaded vs the prior 30%/10% split — Finance Act 2024 simplification).
• Annual investor limit: EUR 500,000 per year (EUR 250,000 standard cap + an additional EUR 250,000 for investments held 7+ years).
• Qualifying SMEs: Must be unquoted, in a qualifying trade, with limited age (under 7 years from first commercial sale generally), and meet financial-health tests.
• Holding period: 4 years minimum (with the additional EUR 250,000 cap requiring 7-year hold).

EII is the principal Irish equity-finance incentive for SMEs alongside the related Start-up Capital Incentive (SCI) for very early-stage companies. The scheme has been progressively reformed to align with EU State Aid rules and to broaden investor participation.

VAT for incorporated businesses

VAT registration thresholds (raised in Budget 2025 effective 1 January 2025): EUR 42,500 services / EUR 85,000 goods. Standard rate 23%, reduced 13.5%, 9% (gas/electricity, hairdressing reverted to 13.5%), 0% (food, books, children's clothing). See Ireland self-employed tax for fuller VAT mechanics applicable to all Irish businesses.

For practitioners managing US-side compliance for Irish companies with US contractors (1099 issuance, W-9 collection, FATCA), Tax1099 handles the US workflow. EUR-USD foreign-currency banking for cross-border business payments routes through WorldFirst.

For the broader Irish tax stack, see the Ireland country overview, Ireland self-employed tax for sole-trader analysis, Ireland capital gains tax for business asset disposals including Retirement Relief, and the Small business tax topic hub for cross-jurisdiction comparison. To find a Chartered Accountant Ireland or CPA Ireland member who handles corporation tax + CRO filings + R&D credits, browse the Ireland tax-pros directory.