Ireland transposed the CSRD on time. That sentence alone puts it ahead of the Netherlands, Austria, and a dozen other member states. But the transposition introduced scope anomalies that lawyers at McCann FitzGerald and Arthur Cox flagged within weeks, and some remain unresolved as of early 2026. I’ve been tracking these issues since S.I. 336/2024 was published, and the situation is genuinely confusing: the Irish regulations say one thing, the directive says another, and the Department of Enterprise has promised clarifying FAQs that haven’t arrived.
S.I. No. 336 of 2024 amends the Companies Act 2014, with sustainability disclosures required in the directors’ report under ESRS and subject to mandatory limited assurance from a statutory auditor or approved sustainability assurance service provider (SASP).
What you’ll learn
- Where the Irish CSRD Regulations (S.I. 336/2024 and S.I. 498/2024) diverge from the directive, and why you can’t rely on the CSRD text alone when advising Irish clients
- Which entities IAASA supervises for CSRD and where the Recognised Accountancy Bodies (RABs) take over for non-PIEs
- How Omnibus I (Directive (EU) 2026/470) changes which Irish entities are in scope, and the transitional uncertainty until Ireland amends S.I. 336/2024
- What a first CSRD assurance engagement looks like for a mid-tier Irish firm, including hours, fees, and the data readiness problems you’ll hit
- How Ireland transposed the CSRD and where the problems are
- Who reports and when (after Omnibus I)
- Assurance requirements for Irish entities
- IAASA’s role and what the regulator found in Wave 1
- Worked example: first CSRD assurance for Brennan Engineering
- What to do now if you’re a mid-tier Irish firm
- Common mistakes
- Frequently asked questions
This guide covers CSRD implementation in Ireland specifically. It does not cover other EU member states (see our EU-wide CSRD guide for that) or the detailed ESRS disclosure requirements by topic. The focus is on what’s different in Ireland and what mid-tier firms need to do about it.
How Ireland transposed the CSRD and where the problems are
Ireland transposed the CSRD by S.I. No. 336 of 2024, which came into effect on 6 July 2024 (the EU deadline). The regulations amend the Companies Act 2014 and the Transparency Regulations 2007. A subsequent instrument (S.I. No. 498 of 2024) addressed some initial concerns. Not all.
The most significant problem is scope. Under the CSRD, sustainability reporting applies to large companies, listed SMEs (excluding micro-entities), and certain subsidiaries of non-EU parents. The Irish Regulations define “applicable company” by reference to the Companies Act 2014’s existing size categories. But the Companies Act treats any Irish company with transferable securities admitted to trading on a regulated market as a “large company,” regardless of its actual employee count, turnover, or balance sheet. Certain listed companies that would be SMEs under the directive face Wave 1 or Wave 2 obligations rather than the lighter SME regime the directive intended.
Arthur Cox noted that the subsidiary exemption (allowing in-scope subsidiaries to rely on a parent’s consolidated sustainability report) was initially confined in the Irish regulations to situations where the EU parent is also Irish. The directive intended the exemption to apply regardless of which member state the parent is in. S.I. 498/2024 partially addressed this, but professional advisors continue engaging with the Department of Enterprise, Trade and Employment on outstanding alignment issues.
For auditors, the practical implication is straightforward: you cannot rely on the CSRD text when advising Irish clients on scope. You need to read S.I. 336/2024 and the Companies Act definitions together. I’ve seen firms advise clients based on the directive text and then discover their client was in scope a year earlier than expected under the Irish definitions. Read the national transposition. Always.
Ireland also enacted the Stop-the-Clock legislation in July 2025, giving legal effect to the EU directive that delayed Wave 2 and Wave 3 obligations by two years while Omnibus I was negotiated.
Who reports and when (after Omnibus I)
The Omnibus I Directive (EU) 2026/470, published 26 February 2026, narrows CSRD scope to EU undertakings exceeding both 1,000 employees and EUR 450 million in net turnover. Member states must transpose by 19 March 2027. Ireland will need to amend S.I. 336/2024 accordingly.
Wave 1 entities (large PIEs previously subject to the NFRD) began reporting in 2025 on FY 2024 data. These are primarily large Irish-incorporated companies listed on Euronext Dublin or other EU-regulated markets. IAASA supervises their sustainability reporting and assurance. Omnibus I gives member states the option to exempt Wave 1 entities below the revised thresholds for FY 2025 and FY 2026. Whether Ireland exercises this option depends on the transposition timeline, which is unclear.
Wave 2 entities (large companies meeting the revised thresholds) first report in 2028 on FY 2027 data. For Irish firms, this is the wave that opens CSRD assurance to non-PIE practitioners. The RABs (CAI, ACCA, CPA Ireland) regulate assurance providers for these entities, as IAASA’s oversight is limited to PIEs.
Listed SMEs are removed from mandatory scope under Omnibus I, though they may voluntarily report using the VSME standard once the Commission publishes the delegated act (expected June 2026). Non-EU parent companies with qualifying Irish subsidiaries report from 2029 onward under revised third-country thresholds (EUR 450M parent turnover in the EU, EUR 200M subsidiary/branch turnover).
One Irish-specific complication worth flagging: because the Companies Act deems all listed companies as “large,” some entities that fall outside scope under Omnibus I’s revised thresholds may still be caught by the existing Irish definitions until S.I. 336/2024 is amended. This creates a transitional period of uncertainty. If you have clients in this grey zone, flag it to them now. Don’t wait for the Department to resolve it.
Assurance requirements for Irish entities
CSRD assurance is not a financial audit with different numbers. It is a fundamentally different engagement: different evidence sources, different subject matter expertise, different professional judgment calls. The sooner you stop thinking of it as “the audit but for ESG,” the better your first engagement will go.
The Irish Regulations require sustainability reporting to be accompanied by a limited assurance opinion. The assurance provider must be a statutory auditor approved for sustainability assurance under Part 28 of the Companies Act 2014, or (once fully operational) an approved SASP.
Ireland permits a different statutory auditor to provide sustainability assurance than the one performing the financial audit. Irish law does not currently permit a non-statutory-auditor IASP to provide the assurance report. The Department of Enterprise held a public consultation on this in 2024 but has not published a final decision.
IAASA issued guidance on SASP approval. Auditors approved before 1 January 2026 could seek approval by demonstrating knowledge of sustainability reporting and assurance. A time-limited exemption from the experience requirement was in place until 31 December 2025. From 2026 onward, both knowledge and relevant experience are required.
For non-PIE firms, the RABs have the power to approve and register SASPs. The Companies Act gives RABs the right to take disciplinary action against auditors who carry out sustainability assurance, with sanctions including fines up to EUR 100,000 multiplied by the number of statutory auditors in the firm. That is not a theoretical risk. The accountability framework is built into the legislation from day one.
The assurance report may be included as a separate section of the audit opinion rather than a standalone report. This simplifies the deliverable for firms providing both financial audit and sustainability assurance to the same client.
Until the EU adopts harmonised limited assurance standards (due 1 July 2027 under Omnibus I), Ireland has the power to adopt a national standard. IAASA hasn’t exercised this. In practice, Irish auditors are working with ISSA 5000 and the CEAOB’s September 2024 guidelines as the interim framework.
How the directors’ report requirement affects your engagement
One structural difference that auditors from other jurisdictions sometimes miss: sustainability information in Ireland is disclosed in the directors’ report, not a standalone sustainability report. The directors’ report is a statutory document under the Companies Act 2014. The directors are personally responsible for its contents. When the sustainability statement sits within the directors’ report, the directors’ liability provisions apply to the sustainability disclosures. This gives CSRD reporting in Ireland a legal weight beyond the directive’s general provisions.
For dual-mandate engagements (same firm does financial audit and sustainability assurance), this creates efficiency but also risk. Climate-related provisions, asset impairments linked to transition risks, and workforce liabilities should tell a coherent story across both the financial statements and the sustainability statement. Where they diverge, something needs adjusting.
For split-mandate engagements (different auditor provides sustainability assurance), the financial auditor retains responsibility for the consistency check on the directors’ report as a whole. A communication protocol between the two auditors should be agreed at planning. At my firm, the engagements where this step got skipped all ran into problems at completion.
The Irish market: what mid-tier firms should know
Ireland’s economy is heavily weighted toward multinationals. Many of the largest companies by revenue are subsidiaries of US, UK, or continental European parents. Under the CSRD, these subsidiaries may qualify for exemption if included in a parent’s consolidated sustainability report under ESRS or equivalent. In practice, a significant number of large Irish entities may not need standalone Irish sustainability reporting.
For mid-tier firms, the most relevant client segment is Irish-headquartered companies above the Omnibus I thresholds. These tend to be in construction, food and agri-business, manufacturing, financial services, and technology. The total market for CSRD assurance in Ireland is smaller than in Germany or France. But for firms that serve this segment, the engagements will be complex (multi-site operations, cross-border supply chains, limited sustainability data infrastructure) and recurring.
IAASA’s role and what the regulator found in Wave 1
IAASA published Wave 1 observations in December 2025, covering both reporting examinations and assurance quality inspections from the first year of CSRD in Ireland. The key messages for auditors: planning time was underestimated across the board, and the double materiality assessment (DMA) needs to be the genuine foundation of the sustainability statement, not a tick-box exercise completed after the reporting decisions have already been made.
The DMA is where most engagements get stuck. Clients think they have sustainability data. What they actually have is a collection of spreadsheets that nobody has ever reconciled, maintained by someone who was given the sustainability brief six months ago on top of their existing role. Nobody has done enough of these engagements yet to know what “good” looks like, and anyone who tells you otherwise is selling something.
IAASA’s remit covers two functions. It examines sustainability statements of entities within its Transparency Directive scope (Irish entities on EU-regulated markets). It also inspects assurance quality at PIE audit firms. For non-PIEs, both functions fall to the RABs.
IAASA launched its 2026-2028 Work Programme identifying CSRD oversight as a strategic priority: continued examination methodology development, ongoing assurance quality inspection at PIE firms, and collaboration with other EU regulators through the CEAOB. For non-PIE practitioners, the signal is clear: IAASA’s standards for PIE firms will set the benchmark the RABs apply when reviewing your work.
The IAASA Insights podcast (Episode 5) covers practical observations from the first year. Worth the 30 minutes if you’re preparing for your first CSRD engagement.
Worked example: first CSRD assurance for Brennan Engineering
Scenario
Brennan Engineering Ltd, Irish-incorporated, based in Cork. 1,300 employees, EUR 510M annual revenue, not listed. Manufactures precision components for automotive and aerospace, with supply chain operations in Germany and Poland. Your firm (a mid-tier Irish practice, CAI member) has been Brennan’s statutory auditor for six years. Brennan falls within the revised CSRD scope under Omnibus I and will first report for FY 2027 (published 2028).
Confirm scope and timeline
Brennan exceeds both Omnibus I thresholds (1,000 employees, EUR 450M turnover). As a large non-listed Irish company, it falls under Wave 2. First obligation: FY 2027 sustainability statement in the 2028 directors’ report. IAASA does not directly supervise this engagement. Your RAB (CAI) oversees assurance quality.
Documentation note: “Scope confirmed per S.I. 336/2024 as amended and Directive (EU) 2026/470. Employee count 1,300 and net turnover EUR 510M exceed both revised thresholds. Non-PIE, RAB-supervised.”
Evaluate the DMA
Brennan’s sustainability team (two people, recently appointed) ran a DMA identifying climate change (ESRS E1), pollution (ESRS E2), own workforce (ESRS S1), and workers in the value chain (ESRS S2) as material topics. Fourteen impact, risk, and opportunity items (IROs) across these topics. Brennan assessed resource use and circular economy (ESRS E5) as not material, citing low packaging intensity and existing metal recycling programmes.
Documentation note: “DMA methodology, threshold definitions, stakeholder engagement records, and final IRO list obtained. Evaluated against ESRS 1 paragraph 38. If simplified ESRS are adopted by September 2026, verify whether changes affect the materiality determination for FY 2027.”
Assess data processes and controls
Scope 1 emissions from natural gas consumption and fleet data. Scope 2 from electricity invoices. Scope 3 limited to purchased goods (spend-based estimates and emission factors) and upstream transport. Workforce data from HRIS. No formal internal controls over sustainability data. The team manually consolidates spreadsheets quarterly. No PY WPs to roll forward because this is a first-year engagement.
Documentation note: “Each material disclosure mapped to data source. Absence of automated controls noted. Expect heavier sub testing, less reliance on controls. Scope 3 limitations (spend-based estimates) flagged as area of estimation uncertainty.”
Design and perform assurance procedures
Scope 1: recalculate from gas meter readings and fleet fuel records. Scope 2: agree to electricity invoices, verify emission factor selection. Workforce: test headcount against payroll, verify H&S incident data. DMA: review methodology, test a sample of IRO assessments, evaluate not-material determinations.
The complication
When your team evaluates Brennan’s decision to assess ESRS E5 (resource use and circular economy) as not material, they discover that 40% of Brennan’s raw materials are imported speciality metals with significant upstream environmental impact. Brennan’s DMA justification focuses on packaging intensity and recycling, but doesn’t address raw material sourcing at all. The assurance team raises this with Brennan’s sustainability team, who hadn’t considered raw material circularity in their assessment.
Brennan needs to either expand the E5 assessment to include raw material sourcing and document why it remains not material, or reclassify E5 as material and add the relevant disclosures to the sustainability statement. After analysis, Brennan expands the assessment and concludes E5 is material for the raw materials pathway but not for packaging. Two additional IROs are added. The sustainability statement is updated before the assurance report is finalised.
Documentation note: “DMA challenge on ESRS E5. Original not-material assessment based on packaging only. Raw material sourcing (40% imported speciality metals) not considered. Client expanded E5 assessment. Two IROs added. Sustainability statement updated. This is exactly the kind of DMA gap IAASA flagged in Wave 1 observations: materiality assessments that are technically complete but miss significant aspects of the business model.”
Prepare the assurance report
Standalone limited assurance report following ISSA 5000 and CEAOB guidelines. Negative-form conclusion. Filed alongside the sustainability statement and directors’ report.
The engagement from planning through reporting took approximately 280 hours: DMA evaluation 50 hours, process understanding and gap assessment 70 hours, substantive procedures 120 hours, review and reporting 40 hours. The key variable is data readiness. Companies like Brennan with manual sustainability data processes need more substantive testing than entities with automated collection. For a mid-tier firm at Irish rates, this is a meaningful engagement.
What to do now if you’re a mid-tier Irish firm
Common mistakes in Irish CSRD engagements
- Underestimating first-year time requirements. IAASA’s December 2025 observations flagged this explicitly. The DMA alone can take 4-8 weeks. The gap between what the client thinks they have and what you actually need is enormous in year one. Most entities have sustainability data in spreadsheets that nobody has ever reconciled against source records. Budget double what you think for year one. I’d estimate 60-70% of first-year hours go to data gathering and gap remediation, not assurance procedures.
- Relying on the directive text instead of the Irish Regulations. The scope anomalies in S.I. 336/2024 (particularly the deemed “large company” treatment for all listed entities) caught several companies off guard. Auditors who read the CSRD without reading the Irish transposition missed the fact that their clients were in scope earlier than expected.
- Ignoring the subsidiary exemption limitations. An Irish subsidiary of a non-Irish EU parent may not be able to rely on the parent’s consolidated report as easily as the directive intended. Verify the exemption conditions under Irish law specifically.
- Accepting a CSRD assurance engagement without SASP approval. The experience exemption expired end-2025. From 2026, a statutory auditor must demonstrate both knowledge and relevant experience. If you haven’t started the approval process, you can’t accept the engagement.
Related content
- Double materiality. The ESRS double materiality concept referenced throughout the DMA evaluation steps in Irish CSRD engagements.
- ESRS IRO Compliance Checker. Free tool for mapping material IROs to ESRS topical disclosure requirements.
- CSRD Compliance 2026: What Auditors Need to Know. The EU-wide companion post covering Omnibus I, limited assurance under ESRS, and the AFM’s quality framework.
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Frequently asked questions
How did Ireland transpose the CSRD?
Via S.I. No. 336 of 2024, amending the Companies Act 2014 and Transparency Regulations 2007. S.I. 498/2024 addressed some initial concerns. Scope anomalies remain, particularly around the deemed “large company” treatment for all listed entities.
Who supervises CSRD assurance in Ireland?
IAASA for PIE audit firms. The RABs (CAI, ACCA, CPA Ireland) for non-PIE entities. IAASA’s standards for PIE firms set the benchmark RABs apply when reviewing non-PIE work.
Can a different auditor provide sustainability assurance?
Yes. Ireland permits a different statutory auditor. However, a non-statutory-auditor IASP is not currently permitted. The assurance report may be included in the audit opinion or issued standalone.
What scope anomalies exist in the Irish transposition?
The Companies Act treats any listed Irish company as “large” regardless of actual size. Some listed SMEs face broader obligations than the directive intended. The subsidiary exemption was also initially limited to Irish EU parents.
When do Irish Wave 2 companies first report?
2028, on FY 2027 data. These engagements can be performed by non-PIE practitioners, with RABs regulating quality. Contact your RAB about SASP approval now.
Further reading and source references
- S.I. No. 336 of 2024, European Union (Corporate Sustainability Reporting) Regulations 2024.
- S.I. No. 498 of 2024: amending instrument.
- IAASA December 2025 Observations: Wave 1 reporting and assurance quality findings.
- Directive (EU) 2026/470 (Omnibus I): the amending directive narrowing CSRD scope.
- IAASA 2026-2028 Work Programme: strategic priorities including CSRD oversight.