Updated: August 2026. Statutory references, the Revenue intervention framework and the small benefit exemption figures below have been reviewed and refreshed.
The short answer: Ireland operates a self-assessment tax system, so the company, not Revenue, carries the responsibility for accurate returns and records. Revenue selects most audits by risk profiling rather than at random, gives written notice with a 28-day window, and that window is the last opportunity to make a prompted qualifying disclosure and cut penalties. The two things that decide how an audit ends are the quality of six years of records and whether every expense claimed meets the “wholly and exclusively” test in section 81 TCA 1997.
Why Compliance Is a Business Strategy, Not an Overhead
Operating a business in Ireland requires adherence to the principle of self-assessment, meaning the ultimate responsibility for accurate, timely filing, and meticulous record-keeping rests entirely with the taxpayer. This responsibility extends across all relevant tax heads, including Corporation Tax (CT), Value-Added Tax (VAT), and Payroll taxes (PAYE/PRSI/USC), each with its own place in the Irish filing calendar.
A proactive approach to compliance should be regarded not merely as a necessary administrative cost, but as a critical mechanism for risk mitigation and a prerequisite for maximising legitimate tax savings. Businesses that maintain robust compliance practices build internal confidence, allowing their financial operations to withstand scrutiny, which is vital for the long-term health and viability of the enterprise.
Conversely, lax compliance practices can trigger severe financial and reputational harm. Non-compliance often leads to the assessment of extra tax owed, mandatory interest charges imposed for late payment, significant penalties, and, in severe cases, the publication of settlement details on the quarterly Tax Defaulters List. Investing in professional, continuous compliance support effectively preserves capital and shields the business from punitive measures that arise from errors or omissions.
Who Revenue is and what governs an audit
The Revenue Commissioners are the Irish state authority tasked with ensuring compliance with tax legislation. A Revenue audit is an examination designed to verify this compliance, achieved by comparing the company’s officially filed tax returns against its underlying financial records.
The entire process, from selection through to settlement, is governed by the Code of Practice for Revenue Compliance Interventions. Since May 2022 that Code sets out a three-level framework, and knowing which level applies matters more than the label “audit”:
- Level 1: self-review notifications, profile interviews and other low-intensity contacts. An unprompted qualifying disclosure generally remains available.
- Level 2: risk reviews and audits. Written notice is issued and a prompted qualifying disclosure becomes the route to reduced penalties.
- Level 3: investigations, where the qualifying disclosure route is closed and criminal prosecution is possible.
Understanding this Code is essential for business owners to know what information Revenue is entitled to request and the formal procedure the auditor must follow.
How Does Revenue Select a Company for Audit?
Revenue audits are rarely random. Selection is based on risk assessment and data profiling through the Risk Evaluation, Analysis and Profiling (REAP) system, which scores taxpayers against sector norms and third-party data to identify anomalies suggesting potential non-compliance. Revenue also runs sectoral projects focusing on industries prone to risk and, occasionally, random checks for verification.
Common audit red flags
- Inconsistent or late tax filings
- Discrepancies between filed returns and third-party data, including payment-processor and bank reporting
- Unusually high or disproportionate expense claims against sector norms
- Personal expenses claimed as business deductions
- Contractor arrangements that may in substance be employment, an area of sharpened focus since the Karshan judgment (see employment classification and taxation)
The official notification: the critical 28-day window
Revenue typically notifies taxpayers of a Level 2 intervention by written notice, giving a 28-day window to prepare. The letter specifies the date, time, tax heads, and accounting periods under review. Upon receipt, contact a tax adviser immediately. The period can in practice be extended, on request, to allow submission of a Qualifying Disclosure (QD), a written admission and correction of errors that can significantly reduce penalties and keep the settlement off the published list.
Phase I: Preparation and Document Readiness
The immediate pre-audit checklist
- Scope confirmation: Verify which tax heads and periods are under review.
- Internal review: Check all financial and payroll records for accuracy.
- Balance sheet integrity: Ensure reconciliations and bad debt provisioning are correct.
- Review returns: Identify and correct potential errors before the audit begins.
Why the qualifying disclosure matters
A Qualifying Disclosure must be in writing, signed, specify the errors, include the amount of tax and interest due, and be accompanied by payment. Benefits include reduced penalties, immunity from criminal prosecution, and exclusion from publication. The QD must be made before the audit officially begins; once the auditor starts examining the books, the opportunity is gone.
Organising your financial records: the six-year rule
Businesses must retain original documentation for at least six years, extended if an issue is under investigation or appeal. Records typically required include sales and purchase invoices, bank statements, payroll records, and expense receipts proving business purpose. Where payroll is outsourced, the employer still owns the retention obligation, so confirm what the provider keeps and for how long.
Best practices for audit-proofing your business
- Keep personal and business finances completely separate, ideally through a dedicated business bank account.
- Document every transaction clearly, including the business purpose.
- Use accounting software and Revenue’s Receipts Tracker for organised digital records.
- Conduct quarterly reviews to catch discrepancies early.
Phase II: The Audit Meeting, Settlement and Appeal
Conduct during the audit
Auditors present identification and explain the audit’s purpose. All communication should be handled through a tax agent, and only documents within the scope of the notice should be shared.
Examination of books and records
Auditors compare filed returns with underlying records, often requesting digital data through Revenue’s secure file transfer channels. Consistent, integrated accounting systems are vital for avoiding discrepancies.
The final interview and settlement
If discrepancies are found, the auditor discusses findings, and the taxpayer agrees a settlement that includes additional tax, statutory interest, and penalties. Once payment is made, an official receipt concludes the audit.
Penalties, interest and publication
Penalty levels depend on the taxpayer’s behaviour (careless or deliberate), whether a disclosure was made and whether it was prompted or unprompted, and on the level of co-operation. Without a Qualifying Disclosure, settlement details may be published on the Tax Defaulters List where the settlement exceeds the statutory threshold and the penalty exceeds the prescribed percentage of the tax.
The appeal process
A taxpayer who disagrees with an assessment can seek an internal review within Revenue and, separately, appeal to the independent Tax Appeals Commission (TAC). A statutory appeal to the TAC must generally be lodged within 30 days of the notice of assessment, so the deadline should be diarised as soon as the assessment issues.
The “Wholly and Exclusively” Rule: Section 81 TCA 1997
Expenditure must be incurred “wholly and exclusively” for the purposes of the trade to qualify for deduction under section 81 of the Taxes Consolidation Act 1997. Where an expense serves a dual purpose, business and personal, the deduction can be restricted or disallowed unless the business portion is clearly identifiable and documented.
Duality of purpose in practice
| Expense Category | Deductibility | Rationale |
|---|---|---|
| Employee wages | Fully deductible | Incurred solely for trade purposes. |
| Client entertainment | Not deductible | Specifically disallowed for tax purposes. |
| Home broadband | Partially deductible | Only the verified business proportion. |
| Computer purchase | Capital allowances | Relieved over time as tax depreciation, not as a revenue expense. |
Pre-trading expenses
Under section 82 TCA 1997, qualifying expenses incurred in the three years before a trade commences, such as registration fees, market research, rent and professional fees, are treated as incurred on the first day of trading and are deductible from that point. Keep those invoices from the formation stage onward, because they are easy to lose and difficult to reconstruct later.
Which Expenses Are Allowable for an Irish Company?
Operational costs
Deductible operational costs include goods for resale, rent, utilities, and business insurances.
Personnel costs
Employee wages, employer PRSI contributions, and employer pension scheme contributions are deductible. Genuine bad debts may also be written off.
Professional and financial fees
Accountancy, legal, and tax services directly related to trading activities are allowable expenses, and interest on loans applied for trade purposes qualifies for deduction. Note that the cost of tax appeal work and certain capital-related professional fees can fall outside the deduction.
Capital expenditure and allowances
Capital assets such as machinery, fixtures or computers are not immediately deductible but qualify for wear and tear allowances, normally at 12.5% per year over eight years for plant and machinery. Accelerated Capital Allowances (ACA) for qualifying energy-efficient equipment allow the full cost to be claimed in the first year; confirm the scheme’s current status and the qualifying equipment list before relying on it.
Complex Deductions and Specific Scenarios
Remote working relief
Two separate mechanisms exist and they are often confused. An employer may pay a tax-free daily allowance towards the additional costs of working from home, or the employee may claim remote working relief through Revenue’s myAccount for a proportion of electricity, heating and broadband costs, apportioned by the number of days worked remotely. Only one route can apply to the same cost, and both require supporting records. Verify the current daily allowance and relief percentage with Revenue before setting a policy.
Travel and subsistence
Travel expenses are deductible only for business journeys, not for ordinary commuting between home and a normal place of work. Companies can reimburse vouched actual costs or use Revenue-approved civil service mileage and subsistence rates, maintaining detailed records for six years.
Small benefit exemption
Employers can give employees non-cash benefits or vouchers free of tax, USC and PRSI under the small benefit exemption. Since 1 January 2025 the exemption covers up to five benefits in a year with a combined cap of EUR 1,500; confirm the current year’s limit with Revenue before launching a scheme, as the figure has been revised in successive budgets. The benefit cannot be cash, cannot be exchanged for cash, and cannot form part of a salary sacrifice arrangement. Used properly it is one of the most efficient rewards available to a small Irish employer, and it is administered through payroll rather than as an informal extra.
Non-deductible items
- Capital costs and accounting depreciation
- Fines and penalties, including Revenue interest and penalties themselves
- Client entertainment and hospitality
- Any expense with a personal element that cannot be apportioned on evidence
Frequently Asked Questions
How far back can a Revenue audit go in Ireland?
Records must be retained for six years and an audit normally examines specified periods within that window. Where Revenue suspects fraud or neglect, the ordinary four-year time limit on raising assessments does not apply, so older periods can be reopened.
How much notice does Revenue give before an audit?
A Level 2 intervention, meaning a risk review or audit, is notified in writing with a 28-day window before the intervention begins. That period is the last opportunity to make a prompted qualifying disclosure.
What is a qualifying disclosure and why does it matter?
It is a signed, written statement of the errors, with the tax and interest calculated and paid. It reduces the penalty, gives immunity from criminal prosecution, and keeps the settlement off the published Tax Defaulters List. An unprompted disclosure, made before any Revenue contact, attracts the largest reduction.
What does “wholly and exclusively” mean for business expenses?
Under section 81 TCA 1997, an expense is deductible only if it is incurred entirely for the purposes of the trade. Where a cost has both business and private elements, such as a home phone or broadband line, only the identifiable and evidenced business proportion can be claimed.
How long must an Irish company keep its records?
Six years from the end of the accounting period, and longer where an appeal, investigation or dispute remains open. This applies to invoices, bank statements, payroll records and the evidence supporting each expense claim.
Working with Chern & Co
Irish tax compliance is complex and data-driven. Partnering with qualified professionals ensures timely preparation, correct liability identification, and management of qualifying disclosures, turning potential audit stress into a structured, controlled process.
Chern & Co Ltd, a licensed Irish trust and company service provider and an authorised CRO electronic filing agent, provides full-cycle support: company formation, tax registration with Revenue, accountancy and bookkeeping, and annual filing and compliance. The aim is to build audit-resilient systems from day one rather than assembling records under a 28-day deadline. Contact us to review where your compliance file stands.
Conclusion: Good Bookkeeping Is the Ultimate Defence
Strong bookkeeping and adherence to the “wholly and exclusively” rule form the foundation of audit resilience. By maintaining six-year records, claiming only evidenced deductions, and keeping filings current against the Revenue calendar, Irish businesses can face a compliance intervention as a process rather than a crisis.
Disclaimer: This article is general guidance on Irish tax compliance and is not tax or legal advice. Rates, thresholds and reliefs change; verify the current position with Revenue or a qualified adviser before acting.
