A company director wakes to find her business's bank accounts frozen. The notification from OFSI (His Majesty's Treasury's Office of Financial Sanctions Implementation, the UK authority responsible for administering and enforcing financial sanctions) arrived the previous evening. The designation is already live. The accounts are already blocked. What happens next – and how quickly a legal team moves – shapes every option that remains.
Judicial review of a designation under OFSI is the primary route by which a designated person challenges the lawfulness of a UK financial-sanctions listing before the High Court of England and Wales. The claim rests on public-law grounds – illegality, procedural unfairness, or irrationality – rather than on a merits re-hearing of the designation decision. As of February 2026, the procedural rules governing this route sit under the Senior Courts Act and the Civil Procedure Rules; OFSI itself operates under the Sanctions and Anti-Money Laundering Act ("SAMLA") and the relevant thematic UK sanctions regulations. Timing is critical: the permission stage alone carries a strict window, and designated persons who act slowly may find the court's jurisdiction to grant interim relief has effectively passed.
This guide walks through the procedure step by step, maps the pitfalls that appear at each stage, and compares the UK route with the parallel mechanisms available under OFAC and the EU regime – because many designations touch more than one jurisdiction.
Step 1: Understand what you are challenging and why it matters
A judicial review of a designation under OFSI challenges the administrative decision to list a person, not the underlying policy of sanctions itself. The court asks whether the decision-maker – His Majesty's Treasury – acted within its legal powers, followed a fair procedure, and reached a conclusion that a reasonable decision-maker could reach on the evidence available at the time. This is a narrower inquiry than a full merits appeal, and understanding that narrowness before drafting the grounds is the foundation of any viable claim.
Who is the designated person? OFSI designates individuals, entities, and ships under SAMLA and the thematic regulations made under it. Once listed on the UK consolidated list, the designated person becomes subject to asset freezes and, depending on the specific programme, to further restrictions such as making funds available prohibitions. Third parties – banks, payment processors, trading counterparties – are legally obliged to freeze assets and may not transact without an OFSI licence. The practical consequence is immediate financial paralysis.
In our experience, clients often arrive having already lost one to two weeks to internal escalation and initial uncertainty about which route to take. That delay matters. The grounds for judicial review are assessed against the evidence available when the decision was taken, not when the claim is filed. An early evidential audit – what did Treasury know, what did they not know, was the claimant given an opportunity to make representations? – is the first act of any competent challenge.
The cross-border dimension is also critical at this stage. A UK designation often shadows or is shadowed by an OFAC listing, an EU Council regulation designation, or both. Which regime is primary for your client's business? Where are the assets actually held? The answers determine whether the judicial review claim in London is the highest priority or whether a parallel EU General Court annulment action, or an OFAC reconsideration petition, should proceed simultaneously. Failing to map this picture before issuing the judicial review claim can mean that relief in London arrives too late, or is moot because the EU freeze has not been lifted.
Step 2: Assess the grounds for challenge
The three classical public-law grounds – illegality, procedural unfairness, and irrationality – each have specific application in the OFSI context, and the strength of each turns on the facts of the individual designation. No ground is stronger in the abstract; the case is built from the evidence.
Illegality asks whether Treasury had the legal power under SAMLA and the relevant thematic regulations to make the designation in the circumstances. Does the claimant meet the criteria for listing set out in the applicable regulations? Have those criteria been correctly construed and applied? The designating authority must operate within the four corners of its statutory power.
Procedural unfairness is often the most productive ground in practice. UK sanctions designations are, by their nature, made without prior notice to the designated person – to prevent asset flight. But natural justice still requires a minimum standard of fairness. Was the claimant given a fair opportunity to know the case against them and to respond, at least after the fact? Where the designation was made on the basis of closed material that cannot be disclosed, the procedural challenge requires particular care; the courts have developed a body of jurisprudence on the limits of gisting and closed proceedings in this context.
Irrationality – sometimes called Wednesbury unreasonableness – challenges whether the decision was one a rational decision-maker could reach on the evidence. The bar is high: the court does not substitute its own view of the merits. But where the designation rests on factually incorrect or evidentially thin material, irrationality grounds can succeed.
In our cross-border practice, a fourth angle is increasingly relevant: incompatibility with the Human Rights Act. A designation that constitutes a disproportionate interference with property rights or with private and family life can be challenged on Convention grounds. This adds a proportionality dimension that English public law does not ordinarily apply under pure Wednesbury review.
Step 3: Navigate the permission stage and interim relief
The permission stage is the gateway to a full judicial review hearing, and it is where many sanctions challenges end – either by failing to secure permission or, more commonly for well-prepared claimants, by provoking an early government response that results in a settlement or a voluntary review. The claim must be filed promptly, and in any event within three months of the designation decision (or such shorter time as a relevant rule imposes). Courts can extend time in exceptional circumstances, but relying on that discretion in a sanctions context is a significant risk.
The grounds are assessed on a paper basis first. The judge considers whether the claim is arguable. At this stage, the claimant does not need to show that the challenge will succeed – only that it raises a serious issue fit for full argument. Grounds that are too vague, or that amount to a disagreement with the policy rather than a challenge to the legality of the specific decision, will be refused permission.
Interim relief is often the most urgent issue. An asset freeze is economically devastating from day one. The claimant can seek an interim order requiring Treasury to grant an OFSI licence pending the full hearing, or – in exceptional cases – an order suspending the designation. The court applies a standard balance-of-convenience test, though the threshold is high when the defendant is a public authority acting under a statutory power to protect national security or financial-system integrity. Have you considered whether an OFSI licence for basic living expenses or legal fees can be obtained as a faster parallel route while the judicial review proceeds?
This is the juncture at which the position above covers the standard case but your facts change the analysis. The nature of the evidence Treasury relied on, whether it was provided through a security-cleared process, and the specific thematic programme under which the designation was made all affect the interim-relief calculus materially.
If a designation has already been served, or if a licence application has been refused, an early review by specialist counsel can preserve options that narrow with time. Contact Calder & Vance at info@caldervance.com for a confidential first assessment.
How does the UK judicial review route differ from the EU and OFAC mechanisms?
The UK judicial review route is a general public-law remedy, not a specialist sanctions-appeal mechanism – and that distinction has practical consequences when you compare it with the EU and US routes available to a simultaneously designated person.
Under the EU regime, a designated person challenges a Council designation before the EU General Court through an annulment action. The action directly contests the validity of the Council regulation that contains the listing. The EU General Court applies a standard of review that, in sanctions matters, has evolved toward a fuller examination of the evidence than classic Wednesbury unreasonableness, though the court still gives a significant margin of appreciation to the Council on security grounds. The procedural timeline for EU annulment actions is typically measured in years, not months, though interim measures can be sought. Where the same facts support both a UK judicial review and an EU annulment action, the two sets of grounds are not always identical – the EU criteria for listing and the evidential basis may differ from the UK thematic regulations.
The OFAC route is different again. OFAC, the US Treasury's Office of Foreign Assets Control, does not provide a direct judicial appeal mechanism comparable to English judicial review or EU annulment actions. The primary administrative route is a reconsideration petition submitted to OFAC requesting administrative delisting. Judicial challenge in the US federal courts proceeds under the Administrative Procedure Act, which applies a limited standard of review to national-security-adjacent executive action. In our experience, US courts have historically shown significant deference to the executive in OFAC designation matters – more so than English courts applying SAMLA. That difference in the standard of review can mean that the London judicial review is strategically the stronger thread, even for a person whose assets are principally held in jurisdictions where OFAC is the operative constraint.
Switzerland's SECO, and the designations made under the applicable Swiss sanctions ordinances, operate through an administrative-law review mechanism that differs again. For a global business facing simultaneous UK, EU, US, and Swiss designations – a pattern we see in complex cross-border matters – the litigation strategy has to sequence these routes deliberately, with attention to how a successful or failed outcome in one jurisdiction may be used in another.
The key divergence for practitioners: the UK route is fastest to permission stage but operates on a narrow Wednesbury standard; the EU route gives a fuller factual review but takes longer; the US route has the most deference to the executive of the three. No single route is universally superior. The answer depends on where the assets are held, which regime's criteria were most thinly applied, and the evidence available.
What are the documentation and evidence requirements?
A judicial review claim in a designation challenge is only as strong as the evidential record underpinning the grounds. The claimant builds the evidence package from multiple sources, and gathering it quickly – often within weeks of a designation – is among the most demanding aspects of the work.
The mandatory starting point is a formal request for the information on which the designation was based. Under SAMLA, Treasury is required to inform the designated person of the reasons for the designation to the extent possible without prejudicing national security or other protected interests. In practice, this disclosure is sometimes limited, particularly where the designation relies on intelligence material. The claimant then seeks further disclosure through the pre-action protocol and, if necessary, through the court's disclosure rules once the claim is issued.
What does a strong evidence package look like? In our experience it contains at minimum: a detailed factual narrative correcting errors or gaps in the stated reasons; supporting documents on ownership and control structures (because a listing may rest on a misidentified relationship to a listed person); financial records demonstrating that the designated assets are not connected to the stated grounds; and expert evidence where the designation involves technical matters such as corporate structures in specific jurisdictions or shipping routing.
One common error is focusing only on the narrative and neglecting the structural evidence. Courts are interested in whether the factual premises of the designation hold. An entity designation that rests on an alleged 50 percent or more ownership link to a listed individual is immediately vulnerable if the share register and corporate filings show a different picture. Does your evidence package speak directly to the stated grounds, or does it argue around them?
Record-keeping discipline is also relevant here. Under the relevant UK financial-sanctions regulations, persons subject to a designation must maintain records of their compliance position. That same discipline, applied to the pre-designation period, can produce the documentation that supports the challenge.
Step 4: Risk flags and when to involve specialist counsel
Several patterns reliably predict difficulty in an OFSI judicial review challenge. Identifying them early prevents a claim from being filed on weak grounds, or from being filed late because the claimant did not appreciate the urgency.
The first risk flag is delay. The three-month limitation period for judicial review runs from the date of the designation decision. Where there is any ambiguity about the precise date – for example, where the designation was made under a general-designation power and the claimant was not directly notified but the listing appeared on the consolidated list – specialist advice should be sought immediately. Limitation issues can defeat an otherwise sound claim.
The second risk flag is the presence of closed material. Where the designation is based wholly or partly on closed intelligence material, the judicial review will involve a more complex procedural track. The government may apply for a closed-material procedure. Handling this correctly requires counsel experienced in national-security public-law proceedings, not only sanctions law.
The third risk flag is the multi-jurisdictional designation. Where the same individual or entity is listed under OFAC, the EU regime, and OFSI simultaneously, the UK judicial review proceeds in parallel with other proceedings. Inconsistent positions taken in different proceedings – or a settlement in one jurisdiction that is misread in another – can damage the overall strategy. Co-ordination through a single instructed team, using local counsel in other jurisdictions, is the most reliable approach.
The fourth risk flag, and the one most frequently underestimated, is the misconception that a judicial review is effectively a re-hearing of the designation on the merits. It is not. Clients who arrive believing that producing evidence that they did not do what the designation alleges will automatically win the judicial review are often disappointed. The court is reviewing the legality of the decision, not substituting its own view of the facts. Winning on irrationality requires showing that no reasonable decision-maker could have reached the designation on the evidence available – a harder task than simply producing contradicting evidence. Setting this expectation correctly from the outset changes how the evidence is organised and how the grounds are drafted.
A micro-scenario illustrates the point. In a recent matter, a trading company in the energy sector found itself designated under UK financial-sanctions regulations following a change in its ownership structure. The designation stated a connection to a listed individual based on the prior ownership position. We reviewed the corporate registry evidence, mapped the actual post-restructuring ownership chain, and identified that the stated grounds rested on a factual position that had changed before the designation was made. The grounds for challenge on irrationality and on the accuracy of the stated reasons were strong. The pre-action correspondence, backed by the evidential package, resulted in a voluntary Treasury review within weeks of the claim being pre-notified. Outcomes vary; we make no promise of the same result in other matters.
Step 5: The myth of the guaranteed administrative route and what to do instead
One persistent misconception among clients approaching an OFSI designation is that the administrative reconsideration route – writing to Treasury to request a review – is a sufficient response on its own, and that judicial review is a last resort reserved for cases that have already failed administratively. This framing is wrong, and acting on it can be costly.
The administrative route and the judicial review route are not mutually exclusive and are not strictly sequential. A reconsideration request to Treasury can and does run in parallel with pre-action correspondence for judicial review. More importantly, filing the judicial review claim – or the pre-action protocol letter – does not require the administrative route to be exhausted first, though a court will consider whether available administrative remedies were pursued when assessing the relief to grant.
Why does this misconception arise? Partly because Treasury's guidance to designated persons emphasises the reconsideration and review process as the primary internal route. That is accurate as a description of Treasury's internal procedure. It does not mean that judicial review is unavailable or that the limitation clock pauses while the administrative process runs. In practice, a designated person who spends the first two months of a three-month limitation window in administrative correspondence, without pre-notifying the judicial review, may find the claim is out of time.
The practical answer is to pursue both routes simultaneously from the outset. The pre-action letter for judicial review puts the defendant authority on notice and often produces a substantive response – or a voluntary review – faster than the purely administrative process. It also preserves the limitation position. We regularly advise clients to treat the two routes as complementary tools, not competing alternatives.
To stress-test your approach to a designation challenge, or to obtain an assessment of the available routes under the OFSI regime and any parallel jurisdictions, contact Calder & Vance at info@caldervance.com.
Related practices
- Delisting evidence package – Australian autonomous sanctions regime – building the factual record for administrative and judicial delisting in Australia
- Judicial review of a designation under OFSI – advanced guide – deeper analysis of closed-material procedures and parallel EU proceedings
- Challenging a SECO designation – Switzerland – administrative-law review and appeal routes under the applicable Swiss sanctions ordinances