A UK-based trading company receives notification from His Majesty's Treasury that it has been designated under UK financial sanctions. Its accounts are frozen. Its counterparties receive the notice and begin severing relationships. The directors ask the obvious question: can this decision be challenged? The answer is yes – but the route is narrower, more procedurally demanding, and more time-sensitive than most businesses expect.
Judicial review of a designation under OFSI rules is the primary mechanism by which a designated person can challenge the lawfulness of a UK financial-sanctions designation before the High Court of England and Wales. The claim is brought against His Majesty's Treasury under the supervisory jurisdiction of the Administrative Court. The governing authority is the Sanctions and Anti-Money Laundering Act ("SAMLA"), which provides both the power to designate and the statutory right to seek ministerial reconsideration and, thereafter, to bring judicial review proceedings. As of March 2026, this remains a developing area of domestic public law, with courts calibrating the intensity of review in sanctions cases.
This briefing covers the legal basis for judicial review of a designation under OFSI, the procedural pathway from designation through reconsideration to the Administrative Court, the grounds on which a claim may succeed, the cross-border dimensions that frequently arise, and the practical risk flags a designated person or their advisers should assess immediately.
What is the legal authority for designating a person under UK financial sanctions?
Under SAMLA, His Majesty's Treasury holds the power to designate individuals and entities under the UK's autonomous sanctions programmes and under programmes that implement UN Security Council obligations. A designation is made by way of a statutory instrument or a listing decision, and it takes legal effect on the date specified in the designation notice. The Treasury acts on the basis of a "reasonable grounds to suspect" standard – a lower threshold than proof to the civil or criminal standard.
The Office of Financial Sanctions Implementation (OFSI) is the body within the Treasury responsible for implementing and enforcing UK financial sanctions. OFSI does not make designation decisions; that power rests with Treasury ministers. OFSI's role is to administer the prohibitions that flow from a designation: licensing, enforcement, and guidance to regulated persons. This distinction matters in a judicial review claim, because the defendant in proceedings challenging a designation is His Majesty's Treasury, not OFSI as a separate respondent.
Where a designation implements a UN Security Council resolution, the UK is bound as a matter of international law by the Council's decision. Judicial review of such a designation raises additional complexity. The domestic court must balance SAMLA's requirements against the UK's treaty obligations. In our cross-border practice, we regularly advise designated persons at the point when the nature of the designation – autonomous versus UN-derived – fundamentally changes the available options.
What is the pre-action route: ministerial reconsideration?
Before bringing judicial review proceedings, a designated person may request a ministerial reconsideration of the designation under SAMLA. This is a mandatory administrative step in practice, though its status as a strict pre-condition before judicial review proceedings is a point that requires careful analysis on the specific facts of each case.
The reconsideration request is submitted to His Majesty's Treasury and should be supported by representations setting out why the designation should be revoked or varied. The Treasury reviews the designation and either upholds it, varies it, or revokes it. If the designation is upheld, the designated person may then pursue judicial review in the Administrative Court.
There is no prescribed form for the reconsideration request. However, the quality of that submission matters considerably. In our experience, a poorly drafted reconsideration request – one that fails to engage with the evidence base that Treasury is likely to hold – can weaken both the administrative outcome and the subsequent judicial review claim. The submission should be treated as the first legal document in a potential litigation sequence, not as a routine letter.
The timing of the reconsideration request relative to any judicial review pre-action protocol obligations must also be managed. Sanctions law changes frequently; the precise procedural interaction between the statutory reconsideration route and the judicial review pre-action protocol should be verified before relying on current practice.
How does judicial review of a designation under OFSI rules operate in the High Court?
Judicial review of a designation is brought in the Administrative Court, which sits within the King's Bench Division of the High Court. The proceedings are governed by the Civil Procedure Rules (Senior Courts Act route) and the judicial review pre-action protocol. The claim form must ordinarily be filed promptly and in any event within three months of the decision being challenged – though designated persons should treat this as a floor, not a target, given the volume of documentation required.
The court's role in judicial review is supervisory. It does not substitute its own judgment for that of the decision-maker. Instead, it asks whether the decision was lawful. The principal grounds available in designation challenges are:
- Illegality: Treasury exceeded its statutory power or misapplied the legal test for designation.
- Procedural impropriety: the designated person was not afforded procedural fairness, for example where closed material was decisive and no adequate mechanism was provided to contest it.
- Irrationality / Wednesbury unreasonableness: the decision to designate was so unreasonable that no reasonable decision-maker could have reached it.
- Proportionality: where Convention rights are engaged (particularly under Articles 6, 8, and Article 1 Protocol 1 of the European Convention on Human Rights), the court applies a proportionality analysis that is more searching than traditional Wednesbury review.
The proportionality ground is often the most substantive in designation cases. A designation freezing all of a person's assets engages their right to property and, where the person cannot meaningfully contest closed material, their right to a fair hearing. Courts have signalled a willingness to apply proportionality with real intensity in cases involving significant restrictions on individual rights – though this does not mean designation decisions are readily quashed.
What is the closed material problem and how is it handled?
Designation decisions are frequently based partly on intelligence material that the government treats as too sensitive to disclose. This creates a structural tension: the designated person cannot see the full case against them, but the court must be able to assess whether the decision was lawful.
In UK national-security and sanctions proceedings, the Closed Material Procedure (CMP) allows the court to examine sensitive material in a closed hearing, from which the designated person and their open lawyers are excluded. A Special Advocate – a security-cleared barrister appointed to represent the designated person's interests in the closed session – may cross-examine witnesses and make submissions on the material, but cannot communicate the content to their client.
The Special Advocate regime presents real constraints. The designated person cannot instruct their Special Advocate once closed material has been shared. The quality of representation in the closed session therefore depends heavily on the open legal team understanding the issues before the CMP begins. We regularly advise on structuring the open case to maximise what a Special Advocate can achieve in closed proceedings. This requires early and sustained engagement with the evidentiary questions, not a reactive posture adopted after the designation notice arrives.
How does the UK judicial review route compare with the EU and UN de-listing routes?
The cross-border dimension is rarely absent in a designation challenge. Many clients find themselves designated under two or more regimes simultaneously – a not unusual position for a person or entity with international operations. Understanding the divergence between routes matters for sequencing and for resource allocation.
Under the EU regime, a designated person brings an annulment action before the EU General Court under the Treaty on the Functioning of the European Union. The grounds of challenge are similar in structure – lack of competence, procedural infringement, violation of the Treaty or any rule of law relating to its application, or misuse of power – but the court's approach to proportionality and its procedural rules differ from the Administrative Court. Disclosure obligations, timelines for a written procedure, and the use of confidential material are all handled differently. The UK High Court is not bound by EU General Court jurisprudence post-Brexit, but that case law remains a material reference point in domestic argumentation.
For UN-derived designations, the primary de-listing mechanism is the petition to the relevant UN Security Council sanctions committee, or – for the ISIL/Al-Qaida regime only – to the UN Ombudsperson. The Ombudsperson route provides a degree of independent review and is the more substantive channel. For all other regimes, the committee route is diplomatic in character and does not provide adjudicative review. Where a UK designation implements a UN measure, a successful domestic judicial review will not lift the UN measure; the individual remains on the UN Consolidated List, and any domestic delisting provides only partial relief.
Canada, Australia, and certain other jurisdictions with which clients have connections maintain their own listing and challenge mechanisms. The Australian autonomous sanctions regime, for example, involves a review process with distinct procedural characteristics. Where parallel designations exist, we advise on a co-ordinated strategy that sequences applications across regimes to avoid prejudicing any one route.
One practical divergence between the UK and EU routes is the disclosure of the legal basis for the designation. Under the EU regime, the Council regulation and the designation decision must state reasons, and those reasons are subject to review for sufficiency. Under SAMLA, the Treasury may withhold the detailed basis for a designation where disclosure would harm national security or international relations. That asymmetry shapes the open evidence available to a designated person at the outset.
The position above covers the standard case. Your facts – the basis for the designation, the regimes involved, the nature of the closed material, and the urgency of the freeze – change the analysis significantly.
For a confidential first assessment of the options under the UK regime and any parallel regimes, contact Calder & Vance at info@caldervance.com.
What are the risk flags a designated person should assess immediately?
Time is the first and most serious risk. The judicial review clock runs from the date of the challenged decision, which in a designation context is typically the date the statutory instrument or listing decision takes effect, not the date the designated person receives notification. A designated person who spends weeks awaiting the outcome of informal dialogue with Treasury before taking legal advice may find the primary limitation period has expired or is imminent. Act on the assumption that time is short from the moment of designation.
Asset preservation is the second immediate concern. Once accounts are frozen and assets are blocked, the practical consequences compound quickly. Trade counterparties disengage. Employment contracts may be difficult to honour. Supply chains interrupt. The question of whether urgent interim relief – an application to lift or suspend the freeze pending review – is available and arguable is one that should be assessed in the first days. Interim relief in judicial review of an executive action is available in principle but is rarely granted in national-security-adjacent cases.
Third, assess the basis of the designation carefully. Is it autonomous? Is it UN-derived? Was it made under a programme that tracks the position of another jurisdiction, such that a licensing application or a delisting in one regime affects the position in another? The answer determines which legal instruments govern, which grounds of challenge are most viable, and whether parallel applications in other jurisdictions are appropriate or counterproductive.
Fourth, consider who else is affected. Where an entity is designated, its subsidiaries, affiliates, and joint-venture partners may find their own operations restricted, either directly by the prohibition or by the practical withdrawal of banking and payment services from any connection with the designated group. In our experience, this secondary impact is often underestimated at the outset. Advising the wider group on what it can and cannot do while the designation stands requires careful attention to the prohibitions in the relevant thematic regulations and any applicable OFSI general or specific licences.
Finally, consider the evidentiary position. What does the designated person know about the basis for the designation? What documentation do they hold that rebuts the factual premise? Have communications with relevant counterparties been preserved? The reconsideration request and any subsequent judicial review claim will live or die on the evidence that can be assembled and presented. Preserving and organising the evidentiary base from day one is not optional.
If a designation has already been received, or if a transaction has been flagged as potentially connected to a designated person, an early review can preserve options that narrow with time. Contact our team at info@caldervance.com to discuss your position.
A common misconception: is judicial review the only option once reconsideration fails?
A persistent myth among companies and individuals receiving a UK designation is that, once ministerial reconsideration fails, judicial review is the only remaining avenue and that it is, in practice, futile.
Neither part of that belief is correct. Judicial review remains a genuine legal remedy. Courts have shown that they will scrutinise the proportionality and rationality of designation decisions, and several challenges in the UK have produced outcomes that were material for the designated person, even where the designation itself was not quashed. Partial quashing, procedural rulings requiring fresh decision-making, and the discipline imposed by impending litigation can each deliver substantive value.
Beyond judicial review, the legal options include: applying for an OFSI-specific licence to permit defined activities notwithstanding the designation; engaging with the Treasury through the ministerial review process more than once where new evidence has emerged; pursuing parallel de-listing applications in other regimes (which may in turn affect the UK position); and, in certain circumstances, engaging with parliamentary or ministerial channels on the proportionality of the measure as applied to specific facts.
In our practice, we regularly advise designated persons who initially concluded that their options were exhausted, only to identify viable routes through a structured analysis of the full designation, the evidence, and the procedural history. What matters is the specific legal basis of the designation and the quality of the evidence available – not the general difficulty of the territory.
Related practices
- Delisting evidence package for Australia – preparing the evidence and representations for the Australian autonomous-sanctions review process.
- Judicial review of a designation under OFSI: further analysis – an extended practitioner analysis of closed material, proportionality, and cross-regime co-ordination.