Hamill v Revenue Commissioners: Limits of EU Rights of Defence and Access to File in Tax Audits Involving the Taxpayer’s Own Documents

1. Introduction

The decision of Quinn J in Hamill v The Revenue Commissioners [2025] IEHC 627 is a significant addition to Irish tax appeal jurisprudence at the intersection of:

domestic principles of fair procedures and constitutional justice, and
EU-law-derived “rights of defence”, including the right of access to the file, as articulated in cases such as Glencore and WEBMINDLICENSES.

The High Court was asked to answer a Case Stated from the Tax Appeals Commission (“TAC”) under s. 949AQ of the Taxes Consolidation Act 1997 (“TCA 1997”), on three questions of law focused exclusively on alleged defects in the process by which Revenue carried out an audit and raised assessments. The taxpayer, a retired farmer, did not challenge the substantive tax findings or the quantum of the assessments (save for corrections voluntarily made by Revenue during the TAC hearing). Instead, he claimed that EU procedural rights had been breached because:

Revenue had obtained extensive documentation from third parties without providing it to him before making the assessments, and
those documents should therefore have been excluded from evidence before the TAC.

The case thus becomes a vehicle for clarifying:

how Glencore and related CJEU case law apply in Irish tax audit and appeal procedures;
the limits of the right of access to the file and “equality of arms” in tax assessments, especially where the disputed documents are the taxpayer’s own;
how a taxpayer’s non-cooperation with an audit affects the assessment of procedural fairness; and
the respective roles of judicial review and TAC appeals in policing alleged procedural unfairness by Revenue.

Ultimately, the High Court held that no breach of EU or domestic procedural rights occurred and that the TAC had not erred in law in admitting the contested material. The judgment establishes an important principle: where the documents obtained by Revenue from third parties are the taxpayer’s own records, of a kind already within the taxpayer’s access or procurement, and the taxpayer is informed of Revenue’s information-gathering and offered opportunities to engage but refuses to cooperate, there is no breach of EU “rights of defence” in not providing those documents to the taxpayer before raising assessments, nor any basis to exclude them at appeal.

2. Summary of the Judgment

2.1 Questions Stated

The Case Stated asked the High Court to answer three questions of law:

Did the TAC fail to protect the taxpayer’s rights under Articles 41, 47 and 51 of the Charter of Fundamental Rights of the European Union (“the Charter”) and thus err in law?
Did the TAC err in law in permitting the admission of evidence procured by Revenue from third parties?
Did the TAC fail to correctly apply the principles set out by the CJEU in Glencore (C‑189/18)?

2.2 Outcome

All three questions were answered in the negative:

No breach of Charter rights (Arts 41, 47, 51) was established.
No error in admitting third-party evidence was found.
No misapplication of Glencore by the TAC was identified.

2.3 Core Reasons

The Court’s reasoning can be distilled into several key propositions:

The contested documents (bank statements, cheques, receipts, invoices) were the taxpayer’s own documents, all items “to which the Appellant himself had access.” This is a crucial factual distinction from Glencore, where the taxpayer sought access to materials (criminal and administrative files regarding suppliers) that were not their own.
The procedural complaint lacked any specification of concrete prejudice: the taxpayer never explained what substantive unfairness arose from the absence of prior disclosure of these documents by Revenue.
The very need for Revenue to obtain the documents from third parties was a direct consequence of the taxpayer’s non-cooperation and failure to disclose accounts. A party cannot create an “evidential deficit” by refusing to engage and then rely on that deficit to attack the fairness of the process.
The taxpayer was informed that Revenue had obtained documents (e.g. cheques from undisclosed accounts), was given opportunities to meet and to be heard over an extended period, and failed to avail himself of these opportunities.
The “process” arguments based on EU law were raised only at the end of the TAC hearing, which the TAC described as an “ambush.” This was a finding of fact not challenged on the Case Stated.
Having regard to the factual findings (which were not disputed), both the TAC and the High Court concluded that there was no unfairness in Revenue’s process and that the requirements of Glencore, WEBMINDLICENSES and the Charter were satisfied.

The judgment thus reinforces a contextual, fact-sensitive approach to EU-based procedural rights, aligned with both CJEU jurisprudence and established Irish principles of fair procedures.

3. Factual and Procedural Background

3.1 The Audit and Assessments

The appellant, Mr Peadar Hamill, was a retired farmer. Following an extended audit over several years, during which Revenue obtained documents from third parties, Revenue concluded that:

the taxpayer had understated his income for 2013–2015; and
he had not charged VAT on agricultural products (including plastic silage wrap) sold in 2013 and 2015.

Initially, Revenue assessed:

Income tax: €247,283.80
VAT: €154,427.30

During the TAC hearing, Revenue acknowledged miscalculations and reduced the assessments to:

Income tax: €237,551.48
VAT: €126,963.97

The scale of the discrepancies was stark. For example:

2013: Declared income €101,812; total lodgements to three bank accounts €971,112.73; expenditure €915,697.24.
2014: Declared turnover €140,319; lodgements €481,401; expenditure €506,080.26.
2015: Declared turnover €251,312; lodgements €544,246; expenditure €413,013.28.

3.2 The Taxpayer’s Explanations (Substantive Issues Not Appealed)

Before the TAC, the taxpayer advanced three explanations for the mismatch between declared income and bank lodgements:

His only income was from cattle sales and a small amount of fertiliser contract work.
He allowed his bank accounts to be used by others on a “facilitation” basis, without personal gain.
He was a bulk buyer and distributor of agricultural products for other farmers.

For VAT, he argued that certain transactions were effectively between another individual and a UK company, and he had merely provided “Euro banking facilities,” so VAT should not arise.

The TAC rejected all of these explanations. Crucially for the Case Stated, none of these substantive findings or the resulting assessments were challenged before the High Court. The appeal was confined entirely to alleged procedural unfairness.

3.3 Revenue’s Use of Third-Party Information

Because the taxpayer failed to engage fully with the audit and did not disclose all his bank accounts, Revenue obtained information from third parties, including:

Bank statements for undisclosed accounts (Ulster Bank and Northern Ireland Bank of Ireland).
Cheques drawn on those accounts.
Receipts/invoices provided by the taxpayer to farmers for supplies of wrap and other agricultural inputs.
Information from nine farmers, five of whom produced receipts/invoices issued by the taxpayer.
Invoices and delivery information from Tama UAT Ltd in Cork showing supplies of wrap, delivered to a Northern Ireland address associated with the taxpayer but sold on in the State without VAT being charged.

The TAC found:

that these documents were all the taxpayer’s own documents or records generated by him,
that he had access to them (or had had access), and
that his lack of cooperation had forced Revenue to procure them by other means.

3.4 The TAC’s Determination on the Process Arguments

At the end of the TAC hearing, after the evidence had concluded, the taxpayer’s solicitor advanced a new line of argument:

that Revenue’s process was invalid because documents were obtained from third parties and not disclosed before the assessments were raised;
that these documents should be excluded from evidence at the TAC hearing; and
that there was an “evidential deficit” which infringed the taxpayer’s rights of defence under EU law, relying particularly on Glencore.

The TAC rejected these contentions. In summary, the TAC held that:

It had no supervisory jurisdiction over Revenue’s investigative process (citing Lee v Revenue Commissioners).
Even if it did, there was no evidence of unfairness by Revenue; on the contrary, Revenue conducted a thorough investigation and offered multiple opportunities for engagement.
The taxpayer’s reliance on Glencore was:
- raised only in closing submissions (amounting to an “ambush”);
- misplaced factually, since there was no allegation of fraud; and
- misdirected, because the documents were the taxpayer’s own, hence he had potential access to them himself.
The claimed “evidential deficit” resulted from the taxpayer’s own refusal to cooperate, not any conduct of Revenue.

Having rejected these process arguments and accepted Revenue’s factual case, the TAC upheld the (revised) assessments.

3.5 The Case Stated

The taxpayer appealed by way of Case Stated under s. 949AQ TCA 1997, confining his challenge to the process issues. Several points are important:

The taxpayer did not dispute:
- the TAC’s findings of primary fact;
- the lawfulness of the methods by which Revenue obtained the documents from third parties; or
- the TAC’s finding that the taxpayer had failed to cooperate with Revenue.
He ultimately accepted that this was not a fraud case, and that the process arguments were raised “late in the day.”
His case was thus focused almost entirely on the implications of EU law (Charter Articles 41, 47, 51 and CJEU case law) for Revenue’s duty to provide documents and for the admissibility of evidence at the TAC appeal.

4. Legal Framework and Precedents

4.1 Case Stated and the Role of the High Court – Mara v Hummingbird

The High Court’s function on a Case Stated is circumscribed. Quinn J relied on the Supreme Court in Mara v Hummingbird [1982] ILRM 421:

The TAC’s findings on primary facts stand unless there is “no evidence whatever” to support them.
The Court may review mixed questions of fact and law (inferences drawn from primary facts), but will interfere only where:
- the TAC has misinterpreted documents or applied the wrong legal test; or
- no reasonable TAC could draw the inferences reached.

Here, the primary factual findings – including the taxpayer’s non-cooperation, the nature of the documents and Revenue’s opportunities offered to the taxpayer – were not challenged. The High Court therefore treated them as fixed and focused on whether the TAC erred in its legal assessment of fairness and EU rights.

4.2 TAC Jurisdiction and “Process” Complaints – Lee, Menolly Homes, Stanley

A recurring theme in tax appeal jurisprudence is the limited remit of the TAC. In Lee v Revenue Commissioners [2022] 1 IR 388, the Court of Appeal (Murray J) explained that:

The TAC is a creature of statute with no inherent jurisdiction.
Its role is to:
- inquire into issues of fact and law relevant to the statutory charge to tax; and
- determine whether an assessment has been properly raised “in accordance with those statutes.”
The TAC does not have jurisdiction to adjudicate on:
- whether Revenue is estopped or bound by legitimate expectation;
- whether liabilities have been compromised; or
- whether defects in the process of issuing the assessment would render it invalid (that is the domain of judicial review in the High Court).

These principles reflect and build upon earlier authorities such as:

Aspin v Estill [1987] STC 732;
Menolly Homes Ltd v Appeal Commissioners [2010] IEHC 49; and
Stanley v Revenue Commissioners [2017] IECA 279; [2018] 1 ILRM 397.

Quinn J notes that while these cases generally confine “process” challenges to judicial review, the precise boundary between what must go by judicial review and what can be considered in an appeal was not decisive in Hamill, because:

the TAC did in fact address the process arguments substantively; and
the High Court’s task was to assess whether the TAC’s legal analysis of those arguments was correct.

Thus, the judgment neither expands nor narrows the TAC’s jurisdictional boundary in the abstract, but assumes (without deciding) that where the TAC does consider alleged unfairness, its reasoning is open to review on a Case Stated.

4.3 EU Law: Charter Rights and “Rights of Defence” – Glencore, WEBMINDLICENSES, Quigley

4.3.1 Charter Provisions

The taxpayer relied on Articles 41, 47 and 51 of the Charter:

Article 41 – Right to good administration:
- Applies directly to EU institutions, bodies and agencies;
- Includes:
  - the right to be heard before an adverse measure;
  - the right of access to one’s file (subject to confidentiality/business secrecy); and
  - the obligation to give reasons.
Article 47 – Right to an effective remedy and to a fair hearing before an independent and impartial tribunal.
Article 51 – Scope:
- The Charter binds Member States only when implementing Union law.
- The Charter does not extend the scope of Union law or create new competences.

In practice, in VAT and some other tax fields governed by EU directives, these Charter rights and associated general principles (such as rights of defence, including access to the file) may apply to national tax authorities because they are implementing EU law.

4.3.2 Glencore (C‑189/18)

Glencore Agriculture Hungary Kft concerned a missing trader intra-Community (“MTIC”) VAT fraud context. The taxpayer argued that tax authorities breached:

the right to a fair hearing;
equality of arms; and
rights of the defence,

by denying access to:

the file relating to criminal proceedings against its suppliers; and
the file relating to inspections carried out on those suppliers and documents underpinning the tax authority’s findings.

The CJEU held, among other points:

Rights of the defence are a general principle of EU law, applicable where an administrative act adversely affects an individual.
An affected person must be placed in a position to make their views known effectively on the information upon which the decision will be based.
The right to be heard is central, but it is not absolute: restrictions are possible if they serve legitimate objectives of public interest and are proportionate.
As a corollary, there is a right of access to the file, again subject to justified restrictions.

Crucially, the CJEU emphasised that any alleged breach must be assessed “by reference to the specific circumstances of each case, including the nature of the act at issue, the context in which it was adopted and the legal rules governing the matter” (Glencore, para 44).

4.3.3 WEBMINDLICENSES (C‑419/14)

The taxpayer in WEBMINDLICENSES challenged the use of evidence obtained in criminal proceedings, arguing that it had not had a genuine chance to respond. The CJEU reiterated that domestic courts must verify whether:

“in accordance with the general principle of observance of the rights of the defence, the taxable person had the opportunity, in the context of the administrative procedure, of gaining access to that evidence and of being heard concerning it.” (para 91)

The focus is again on opportunity: access to evidence and being heard about it in the administrative phase, rather than necessarily complete or immediate disclosure of every document.

4.3.4 Quigley v Revenue Commissioners [2023] IEHC 244

In Quigley, Phelan J synthesised the CJEU case law, including Glencore and WEBMINDLICENSES, and linked it to Irish constitutional fair procedures:

Irish common-law fairness and constitutional justice principles already reflect the requirements of EU procedural rights.
While there is a right of access to documentation, this right is not unfettered, just as domestic law does not recognise an absolute right of access to documents.
Where access to information is conceived as part of a “right of defence” under EU law, it particularly arises where there is an imputation against a taxpayer which can only be properly addressed if the taxpayer has access to materials forming the basis for that imputation.

Quinn J explicitly endorsed this approach in Hamill, treating EU procedural rights as aligned with, but not materially broader than, long-standing Irish principles of fair procedures.

4.3.5 TJ v Criminal Assets Bureau [2008] IEHC 168

The TAC cited Gilligan J’s dictum in TJ v CAB, quoted later in Menolly Homes, that:

“since an assessment can only relate to the applicant’s own income and gain, any materially relevant matter would have to be or have been in the knowledge and in the power procurement and control of the applicant.”

This underpins the view that where the evidence concerns the taxpayer’s own affairs and records, it is inherently within their potential control and knowledge. That principle becomes central in Hamill to distinguishing Glencore and framing the scope of any “access to file” entitlement.

4.3.6 TAC Determination 31TACD2023

The taxpayer relied on a previous TAC decision (31TACD2023) in which the same Commissioner had found that the appellant:

was not given access to any evidence, and
was not given an opportunity to be heard before the assessment was raised.

As a remedy, the TAC held in that case that it was “obliged to disregard all of the evidence proffered by the Respondent.”

In Hamill, both the TAC and Quinn J found that this earlier decision was factually distinguishable: the level of engagement, access and opportunity offered to Mr Hamill was materially greater, and the documents were his own.

5. The Court’s Legal Reasoning

5.1 Contextual Assessment of Fair Procedures

Quinn J emphasised that allegations of procedural unfairness, whether grounded in domestic law or in EU rights (including Glencore), must be assessed in context:

“The specific requirements of the principles of fair procedures should always be seen and considered in context. Irish jurisprudence makes that clear and the decision in Glencore itself makes this clear; see para 44 where the CJEU states ‘the question whether there is a breach of the rights of the defence must be examined by reference to the specific circumstances of each case’.”

The Court therefore did not treat the right of access to the file as a rigid or mechanical entitlement; instead, it evaluated:

the nature of the documents;
the taxpayer’s own conduct;
the opportunities afforded to the taxpayer; and
whether any real prejudice or “evidential deficit” existed in substance.

5.2 The Nature of the Documents: They Were the Taxpayer’s Own

A central factual finding by the TAC (unchallenged on the Case Stated) was that:

“the evidence procured by the Respondent, such as the Appellant’s own bank account statements, invoices/receipts provided by him to purchasers of wrap and other agricultural supplies, and copy cheques drawn on his account, were all items to which the Appellant himself had access.” (TAC para 97)

This had several important consequences:

It distinguished the case from Glencore, where the taxpayer was denied access to third-party files (criminal/inspection files on suppliers) that they had not previously possessed.
It made it inherently more difficult to argue that there was an “evidential deficit” impairing the taxpayer’s defence when, in principle, he could have obtained or retained these documents himself.
It framed the discussion of fairness around whether Revenue had to re-supply to the taxpayer documents that were originally his, particularly in circumstances where he had failed to disclose them.

On this point the Court was explicit: the fact that the documents were the taxpayer’s own was a major distinguishing feature from cases like Glencore, involving foreign or third-party material outside the taxpayer’s possession.

5.3 No Identified Substantive Unfairness or Prejudice

Quinn J stressed that, even assuming EU rights of defence were engaged, the taxpayer failed to articulate:

what exactly he could not do because the documents were not disclosed earlier; or
how earlier disclosure would have made any difference to his ability to defend himself or to the TAC’s assessment of the evidence.

The judgment notes:

“at no point was it made clear what substantive unfairness or actual problem was alleged to have been created for the Taxpayer by not having received the documents from the Revenue.” (para 44)

Procedural rights are not abstract; they are concerned with ensuring that the person affected has a real opportunity to put forward their case. Where a taxpayer cannot identify any concrete prejudice arising from the alleged failure of disclosure, a claim of breach is likely to fail.

5.4 The Taxpayer’s Non-Cooperation and Its Consequences

The Court attached substantial weight to the taxpayer’s own behaviour:

He failed to disclose all his bank accounts despite being asked.
He failed to cooperate with the audit to the extent that Revenue was “obligated” to obtain information from third parties.
He (through his accountant) effectively shut down communication by letter of 23 October 2017, saying he was “not prepared to continue his assistance or cooperation.”

The TAC had found, and the High Court accepted, that:

“given his non-cooperation with the Respondent’s investigation, the Commissioner would not agree that the Appellant’s right to defence had been breached. The Commissioner does not consider that the Appellant was at an ‘evidential deficit’ as claimed by him, in circumstances where he refused to engage with the Respondent, which was therefore obliged to utilise other methods of procuring the evidence to allow it to properly review and analyse the Appellant’s tax affairs.” (TAC para 98; endorsed at para 46 of the judgment)

This reasoning reflects a broader principle: a party cannot rely on a lack of information that is the direct consequence of its own refusal to engage with a process designed to elicit that information. EU “rights of defence” do not create a shield for taxpayers who deliberately obstruct an audit and then claim unfairness because Revenue proceeded without their cooperation.

5.5 Opportunities to Access Information and Be Heard

Quinn J examined the TAC transcripts to assess whether, in the WEBMINDLICENSES sense, the taxpayer had the “opportunity… of gaining access to that evidence and of being heard concerning it.” The evidence showed that:

Revenue wrote to the taxpayer stating that it had obtained cheques from undisclosed accounts.
Revenue offered meetings on at least two occasions; the taxpayer failed to respond or attend.
Revenue engaged over a period of about two years to establish the correct position.

When cross-examined as to whether the taxpayer had a “fair opportunity to defend himself prior to the making of the assessments”, the Revenue officer replied affirmatively, and this evidence was not seriously challenged.

Quinn J concluded that:

“these findings of fact confirm that the Taxpayer was given appropriate (bearing in mind these were documents that he had or, at one time, had) and sufficient opportunities to gain access to the information and to be heard about the information; this meets the test as set out in WEBMINDLICENSES at para 91.” (para 52)

The Court thereby applied EU case law as a standard for evaluating opportunities, and held that on the facts that standard was met.

5.6 Timing of the Process Arguments – The “Ambush”

The TAC noted that reliance on Glencore was raised for the first time in closing submissions, with no earlier allegation that rights of defence had been breached. The TAC described this as an “attempt to ambush the Respondent at a very late stage,” and this characterisation was not challenged on appeal.

While not the central basis of the High Court’s decision, this finding underscores the importance of:

raising procedural fairness objections early, particularly in a specialist tribunal process; and
not reserving such objections as a tactical device until after the evidence has been fully ventilated.

In practice, this will likely influence how both the TAC and higher courts view late-raised EU law arguments in future cases.

5.7 Admissibility of Third-Party Evidence

Given:

the lawfulness of Revenue’s methods in obtaining the documents;
the fact that the documents were the taxpayer’s own or within his control;
the opportunities given to him to engage; and
the absence of any real prejudice,

the High Court held that there was no error of law in the TAC’s decision to admit the evidence at the appeal hearing. The mere fact that material was obtained from third parties does not, of itself, create an EU law obligation to exclude that material at the appeal stage where due process has been substantively observed.

5.8 Application (and Limitation) of Glencore

Finally, Quinn J addressed directly whether the TAC had misapplied Glencore:

Glencore arose in the context of alleged fraud and reliance on third-party files not belonging to the taxpayer; by contrast, in Hamill, there was no allegation of fraud and the documents were the taxpayer’s own.
Even if Glencore-style rights of defence apply outside the fraud context, they do so in a fact-specific manner, and the key test is whether the person had a real chance to know and comment on the evidence used against them.
On the unchallenged facts found by the TAC, that test was satisfied. Therefore, no misapplication of Glencore occurred.

In effect, the Court adopts Glencore as part of the benchmark of fairness but clarifies its limits in a non-fraud case involving a non-cooperative taxpayer whose own documents are at issue.

6. Complex Concepts Simplified

6.1 Case Stated vs Judicial Review

Case Stated (s. 949AQ TCA 1997):
- A mechanism for appealing a TAC determination to the High Court on points of law only.
- The TAC prepares a “Case Stated” summarising the facts found and the questions of law; the High Court answers those questions on the basis of that record.
- The High Court generally accepts the TAC’s findings of primary fact unless plainly unsupported by evidence (Mara v Hummingbird).
Judicial Review:
- Proceedings in the High Court challenging the legality of the decision-making process of a public authority, including Revenue.
- The focus is on procedural fairness, lawfulness, and jurisdiction, not on the merits of the tax assessment.
- Often the proper route for challenging how Revenue conducted an audit or issued an assessment (per Lee and related authorities).

In Hamill, the High Court sidestepped deciding whether the taxpayer ought to have proceeded by judicial review, because the TAC had already engaged with the fairness arguments in its Determination.

6.2 “Rights of Defence” and “Access to the File”

Rights of defence (EU law):
- A general principle that a person must be able to:
  - know the case against them; and
  - present their views and evidence before an adverse decision is made.
- Includes the right to be heard and, as a corollary, the right of some degree of access to the file.
Access to the file:
- Not an absolute right to every document in every circumstance;
- Must be “sufficient” to enable the person to understand and challenge the grounds for the decision, bearing in mind legitimate confidentiality and public interest concerns;
- In tax cases, especially those involving fraud, this may require disclosure of key materials underpinning allegations, subject to limitations.

6.3 “Implementing Union Law” – Charter Article 51

The Charter binds Member States only “when they are implementing Union law.” In taxation, this typically includes:

VAT (governed by the EU VAT Directive), and
other areas where EU directives or regulations establish tax obligations or procedural frameworks.

In such contexts, national revenue authorities must respect EU rights (including rights of defence) alongside domestic constitutional requirements. In Hamill, the Court proceeded on the basis that EU procedural standards were relevant, particularly because of the VAT aspects, but concluded that those standards had been satisfied on the facts.

6.4 “Evidential Deficit”

An “evidential deficit” would arise if a party genuinely lacks access to information needed to challenge allegations made against them, such that the process is effectively one-sided. In this case:

The TAC and High Court rejected the claim of an evidential deficit because:
- the relevant documents were the taxpayer’s own; and
- any deficit stemmed from the taxpayer’s own failure to cooperate and disclose information.

7. Impact and Implications

7.1 For Taxpayers and Advisors

The judgment carries several clear messages for taxpayers and practitioners:

Non-cooperation is a risky strategy.
A taxpayer who refuses to engage with an audit, withholds information or instructs Revenue not to contact them further cannot later credibly complain that they were at an “evidential deficit” or that the process was unfair because Revenue gathered information elsewhere.
Own documents: limited access rights argument.
Where disputed documents are the taxpayer’s own records (bank statements, invoices, cheques), it will be difficult to sustain a claim that EU rights of defence require Revenue to have re-furnished those documents before assessment, absent some special circumstance (e.g. the taxpayer genuinely no longer has them and asked for copies).
Raise procedural objections early.
Arguments based on Glencore, the Charter or fair procedures should be raised as soon as the alleged defect arises. Leaving them until closing submissions risks the court characterising them as an “ambush,” which may undermine their credibility and practical force.
Process vs merits: choose the right forum.
Serious objections to how Revenue conducted an audit (e.g. alleged abuse of powers, systemic unfairness, improper use of information) may need to be brought by judicial review rather than as part of an appeal on the merits.
Identify specific prejudice.
Bare assertions that “rights of defence” or “fair procedures” have been breached are unlikely to succeed. Practitioners should be prepared to explain:
- what information was missing;
- how that impeded the client’s ability to defend themselves; and
- how the outcome might have been different had fair procedures been followed.

7.2 For Revenue

For Revenue, the decision offers both reassurance and guidance:

Reassurance:
The High Court has confirmed that, provided:
- the taxpayer is informed of the fact that information is being gathered;
- they are given genuine opportunities to cooperate, meet and respond; and
- the documents relate to the taxpayer’s own affairs,
the failure to physically supply every document prior to assessment will not automatically breach EU rights of defence.
Best practice remains important:
Even though the Court found no breach here, Revenue would be well advised to:
- clearly notify taxpayers when third-party information about them is obtained;
- offer access to that material, particularly if requested; and
- keep records of offers of meetings and communications, as these were decisive in Hamill.
Fraud and third-party files remain sensitive.
The judgment does not dilute Glencore in fraud or MTIC cases, where critical evidence may be held in third-party criminal or administrative files. Revenue must continue to respect EU rights of defence in such contexts and consider proportionate disclosure or summaries.

7.3 For the TAC and the Courts

The decision also has institutional implications:

Confirmation of a contextual, evidence-based approach.
The TAC’s factual findings on cooperation, communication and access opportunities were central and were upheld. This confirms that the TAC’s primary-fact findings will be respected on Case Stated appeals if properly grounded in evidence.
Process arguments within appeals.
While Lee and related authorities suggest that many process complaints should be left to judicial review, Hamill shows that:
- the TAC may, in appropriate cases, engage with fairness arguments; and
- when it does so, the High Court will review its legal reasoning through the Case Stated mechanism.
Distinguishing fact patterns like 31TACD2023.
The High Court implicitly endorses the idea that, where a taxpayer is given no access to evidence and no opportunity to be heard before assessment, there may indeed be circumstances where the TAC must disregard evidence. But Hamill clarifies that this is not a general rule: much turns on whether opportunities were in fact offered and whether the taxpayer took them.

8. Conclusion

Hamill v Revenue Commissioners [2025] IEHC 627 is a carefully reasoned judgment that situates EU “rights of defence” and access-to-file principles within the broader framework of Irish fair procedures and tax administration.

The key takeaways are:

EU procedural rights are contextual, not absolute.
Rights derived from Glencore, WEBMINDLICENSES and the Charter must be applied by reference to the circumstances of each case, including:
- the nature of the documents;
- whether they are the taxpayer’s own;
- the taxpayer’s own conduct; and
- whether any real prejudice resulted.
Where the documents are the taxpayer’s own and the taxpayer refused to cooperate, there is no inherent unfairness in Revenue obtaining and using them via third parties.
In such scenarios, the failure to provide copies of those documents before raising assessments does not, without more, breach EU rights of defence or domestic fair procedures.
Opportunities, not perfection, are what matter.
What EU and domestic law require is that the taxpayer has a genuine opportunity to know the basis of the case against them and to respond. In Hamill, the multiple offers of meetings and correspondence over a two-year period satisfied this requirement.
Non-cooperation undermines fairness claims.
A taxpayer cannot rely on a supposed “evidential deficit” that arises from their own refusal to disclose information or engage with an audit.
Process challenges should be timely and, where appropriate, pursued via judicial review.
Raising EU law-based fairness complaints only at the conclusion of a TAC hearing is disfavoured and may be characterised as an “ambush.”

In broader legal context, the judgment consolidates a line of Irish authority – from Menolly Homes to Lee to Quigley – confirming that Irish fair procedures are, in substance, compatible with EU procedural standards, while also emphasising the practical and fact-sensitive nature of fairness in tax administration. For practitioners, Hamill provides a clear roadmap for analysing and litigating future disputes about access to documents, process fairness, and the admissibility of evidence obtained from third parties in tax cases.