TRW & Co · Public law
Judicial Review: Grounds, Time Limits and Process
Judicial review lets the High Court check whether a public body acted lawfully. This judicial review UK guide explains the grounds of illegality, irrationality and procedural unfairness, the rule that claims must be brought promptly and within three months, the permission stage, and the remedies available in the Administrative Court in England and Wales.
Key pointFiling within three months is not a safe harbour: the claim must also be prompt, the pre-action protocol does not stop the clock, and planning and procurement challenges have much shorter limits.
At a glance
Three-month outer limit
Under CPR 54.5 a claim must be filed promptly and not later than three months after the grounds arose; parties cannot extend this by agreement.
Shorter special limits
Planning challenges must be filed within six weeks, and procurement challenges follow the shorter limits in the procurement legislation.
Permission required
Section 31 of the Senior Courts Act 1981 requires the High Court's permission and a sufficient interest before a claim can proceed.
Three classic grounds
Illegality, irrationality and procedural impropriety, set out in the GCHQ case, plus legitimate expectation and human rights grounds.
Discretionary remedies
Quashing, mandatory and prohibiting orders and declarations; relief must be refused if the outcome would highly likely have been the same.
Swipe or scroll →
Judicial review UK: the short answer
Judicial review is the process by which the High Court checks whether a public body has acted lawfully. This judicial review UK guide focuses on England and Wales, where claims are heard in the Administrative Court. The court does not ask whether a decision was right or wrong on the merits. It asks whether the decision-maker acted within its powers, followed a fair procedure and reached a decision that was rational.
Three features shape every claim. First, the time limit is short: the claim form must be filed promptly and in any event within three months of the grounds arising, and sooner in planning and procurement cases. Second, the claimant needs the court's permission to proceed, which filters out weak claims early. Third, remedies are discretionary, and the court must refuse relief if it is highly likely the outcome would not have been substantially different.
Judicial review is usually a last resort. If there is a right of appeal, a complaints process or an ombudsman, the court will normally expect it to be used first.
Who uses judicial review
Claimants range from individuals challenging immigration or housing decisions to businesses challenging licensing, regulatory, tax and planning decisions, and campaign groups challenging government policy. Companies affected by decisions of regulators, local authorities or ministers often find that judicial review UK proceedings are the only route to court.
The legal framework
The procedure is set out in section 31 of the Senior Courts Act 1981 and in Part 54 of the Civil Procedure Rules. Section 31 requires the leave, or permission, of the High Court and a "sufficient interest" in the matter. The court has published the Administrative Court Judicial Review Guide, which explains practice in detail and is essential reading for anyone bringing or defending a claim.
The Judicial Review and Courts Act 2022 added new powers to make suspended quashing orders and to limit the retrospective effect of a quashing order. Where Convention rights are engaged, the Human Rights Act 1998 requires public authorities to act compatibly with them, and proportionality becomes part of the analysis.
Which decisions can be challenged
Judicial review applies to public bodies exercising public functions: government departments, local authorities, regulators, tribunals without a right of appeal, and some private bodies carrying out public functions. Purely contractual or commercial disputes with a public body are normally private law matters. Immigration judicial reviews are generally heard by the Upper Tribunal rather than the Administrative Court, and planning cases go to the specialist Planning Court.
Grounds for judicial review
The classic statement of the grounds comes from the House of Lords in Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374, often called the GCHQ case. Lord Diplock grouped them under three headings, which remain the starting point for judicial review UK claims today.
| Ground | What it means | Typical examples |
|---|---|---|
| Illegality | The decision-maker misunderstood or exceeded its legal powers | Acting outside statutory powers; fettering discretion; taking irrelevant factors into account |
| Irrationality | The decision was so unreasonable that no reasonable decision-maker could have reached it | Illogical reasoning; ignoring obviously material evidence |
| Procedural unfairness | The process was unfair or did not follow required procedures | No consultation where required; bias; failure to give reasons |
| Legitimate expectation | A clear promise or established practice was departed from unfairly | Breaking an unambiguous assurance on which the claimant relied |
| Human rights incompatibility | The decision breaches a Convention right under the Human Rights Act 1998 | Disproportionate interference with property or private life |
Illegality
Illegality covers any error about the scope of the decision-maker's power. A body that misreads its statute, uses a power for an improper purpose, applies a rigid policy without considering exceptions, or delegates a decision it should take itself, acts unlawfully. Many successful claims turn on careful statutory interpretation.
Irrationality
Irrationality is a high threshold. The court will not substitute its own view. It intervenes where the reasoning is illogical, where an obviously material factor was ignored, or where the outcome falls outside the range of reasonable responses. Claims based on irrationality alone are often weaker than those based on legal error.
Procedural unfairness
Fairness depends on context. Where a statute prescribes a procedure, it must be followed. Where it does not, common law fairness may still require consultation, disclosure of the case against a person, an opportunity to respond, and a decision-maker free from bias. Consultations must be conducted properly, at a formative stage and with enough information to allow an intelligent response.
Judicial review UK time limits: the promptness rule
Under CPR 54.5, the claim form must be filed promptly and in any event not later than three months after the grounds to make the claim first arose. The parties cannot extend this by agreement. Filing within three months is not automatically enough: a claim can be refused for lack of promptness if the claimant delayed without good reason, particularly where third parties have relied on the decision.
Shorter limits apply in specific areas. Challenges to planning decisions under the planning Acts must be filed within six weeks. Challenges to procurement decisions follow the time limits in the procurement legislation, which under the Procurement Act 2023 is generally 30 days from knowledge. Claims under the Human Rights Act 1998 have their own time limit.
Time runs from when the grounds first arose, usually the date of the decision, not from the end of correspondence. The pre-action protocol does not stop the clock. If a deadline is close, file the claim and continue negotiating, rather than risk losing the right to challenge.
The judicial review process step by step
A typical claim in the Administrative Court follows a well-established path. The timings below reflect the Civil Procedure Rules and the pre-action protocol.
- Pre-action letter. Send a letter before claim under the Pre-Action Protocol for Judicial Review, identifying the decision, the grounds and the remedy sought. The defendant should normally respond within 14 days. Urgent cases may skip this step. Our guide to the letter before claim explains the general principles.
- Consider alternatives. The protocol expects parties to consider alternative dispute resolution, internal review and ombudsman routes. Refusing reasonable proposals can affect costs.
- File the claim form. File the claim promptly and within the time limit, with a statement of facts and grounds, the decision under challenge and supporting evidence. Disclose all material facts, including those unhelpful to you.
- Acknowledgment of service. The defendant and interested parties file an acknowledgment of service, with summary grounds of resistance, not more than 21 days after service of the claim form.
- Permission decision. A judge usually decides permission on the papers, asking whether the claim is arguable. If refused, the claimant may ask for reconsideration at an oral hearing within 7 days of service of the reasons.
- Full hearing. If permission is granted, the defendant files detailed grounds and evidence, and the claim proceeds to a substantive hearing, usually without oral evidence or cross-examination.
- Judgment and remedy. The court decides whether the decision was unlawful and, if so, what remedy to grant. Appeals lie to the Court of Appeal with permission.
Where urgent interim relief is needed, for example to stop a decision taking effect, an application can be made with the claim form, and out of hours if necessary.
Remedies in judicial review UK claims
The court can make a quashing order, which sets the decision aside; a mandatory order, which requires the body to act; a prohibiting order, which stops it acting unlawfully; and a declaration or an injunction. Damages are available only in limited circumstances, such as where a Convention right has been breached and compensation is necessary.
Remedies are discretionary. Section 31(2A) of the Senior Courts Act 1981 requires the court to refuse relief if it is highly likely that the outcome would not have been substantially different had the conduct not occurred, unless there is an exceptional public interest. Since the 2022 Act, a quashing order may also be suspended or limited in its retrospective effect.
In practice, a quashing order often means that the decision is retaken, sometimes with the same outcome reached lawfully. Claimants should be realistic about what success will achieve.
Standing, evidence and costs
The claimant must have a sufficient interest in the matter. Individuals and businesses directly affected by a decision usually satisfy this easily. Campaign groups and representative bodies may also have standing where they raise a genuine public interest, although the court looks at their expertise and connection to the issue. Other people directly affected can take part as interested parties, and the court may allow interveners to make submissions.
Evidence is mainly in writing. The court decides most claims on witness statements and documents, and cross-examination is rare. The defendant's duty of candour means it must explain its decision-making fully and fairly, which often brings important documents to light after permission is granted.
Costs normally follow the event. A successful claimant usually recovers a large part of its costs, while an unsuccessful one pays the defendant's. Funding options include private funding, legal aid for eligible individuals, crowdfunding and, in some cases, conditional fee arrangements. Costs protection is available in certain environmental claims, so early advice on exposure is worthwhile.
An illustrative scenario
This example is illustrative only and uses generic parties. A regional operator holds a licence from a local authority. The authority adopts a new policy and revokes the licence without giving the operator the chance to respond to a key report relied on in the decision.
The operator takes advice within a week. Its lawyers identify two arguable grounds: procedural unfairness, because the report was never disclosed, and illegality, because the policy was applied rigidly without considering exceptions. They send a pre-action letter and, with the response still outstanding, diarise the three-month deadline and the need to act promptly because the authority is re-tendering licences.
The authority agrees to reconsider after receiving the letter, disclosing the report and inviting representations. The dispute is resolved without issuing proceedings. Many judicial review UK disputes end this way, which is why a focused, well-evidenced pre-action letter matters.
Risks and common mistakes
Treating judicial review as an appeal
The court reviews legality, not merits. Arguing that a decision was wrong, or that the decision-maker should have preferred your evidence, rarely succeeds. Claims framed as disagreements with the outcome are likely to be refused permission.
Identify specific legal errors, unfairness or irrationality, and tie each ground to the statute, policy or evidence.
Missing the promptness requirement
Waiting until the end of the three-month period can be fatal, particularly where third parties have acted on the decision. Planning challenges have a six-week limit, and procurement challenges shorter still.
Take advice as soon as the decision is received and diarise the earliest relevant deadline.
Failing to use alternative remedies
If a statutory appeal, internal review or ombudsman route is available, the court will usually expect it to be pursued first. A claim brought too early may be refused permission.
Check the available routes and record why any alternative is inadequate, such as urgency or the limited powers of the alternative body.
Underestimating costs exposure
The usual rule is that the losing party pays the winner's costs. Claimants may also bear the costs of resisting permission. Costs protection exists in some environmental cases and through cost capping in limited circumstances, but it is not automatic.
Budget for adverse costs, consider whether costs protection applies and weigh settlement options. Where advocacy in the higher courts is required, we instruct specialist counsel.
Incomplete disclosure
Claimants must disclose all material facts, including those that harm their case. Defendants have a duty of candour to explain the decision-making process. Failure on either side can lead to adverse findings or costs.
Gather documents early, request reasons and relevant materials in the pre-action letter, and review them carefully.
Scotland, Northern Ireland and international parties
Judicial review exists across the UK, but procedure differs. In Scotland, applications go to the Court of Session under its own rules and time limits. Northern Ireland has its own High Court procedure. A challenge to a UK-wide decision may need to be brought in a particular jurisdiction, so advice on forum matters.
Overseas companies and individuals can bring judicial review UK claims where they are affected by a UK public body's decision, such as sanctions designations, licensing, regulatory action or immigration decisions. Our guides to appealing a visa refusal and to public inquiries cover related routes.
Checklist: before you challenge a decision
- Obtain the decision, the reasons and the material the decision-maker relied on.
- Calculate the deadline from the date the grounds arose and check for shorter limits.
- Check for appeals, reviews and ombudsman routes.
- Identify specific grounds: illegality, irrationality, unfairness, expectation or human rights.
- Decide what remedy would actually help.
- Send a protocol-compliant letter before claim.
- Assess costs exposure and funding.
TRW & Co's London office is authorised and regulated by the Solicitors Regulation Authority. Our public law and judicial review team advises claimants, defendants and interested parties, including businesses facing planning and regulatory decisions. To discuss a potential claim, contact us at info@trw.co or +880 1779 127165.
Frequently asked questions
01What is the time limit for judicial review?
In England and Wales, CPR 54.5 requires the claim form to be filed promptly and in any event not later than three months after the grounds to make the claim first arose. The parties cannot extend the time limit by agreement. Planning challenges must be filed within six weeks, and procurement challenges within the shorter limits set by procurement legislation. A claim filed within three months can still be refused if the claimant delayed unreasonably.
02What are the grounds for judicial review?
The traditional grounds, set out in the GCHQ case, are illegality, irrationality and procedural impropriety. Illegality covers errors about the extent of a decision-maker's powers. Irrationality covers decisions no reasonable decision-maker could reach. Procedural impropriety covers unfair processes and failures to follow required procedures. Courts also recognise legitimate expectation and, under the Human Rights Act 1998, incompatibility with Convention rights, which may involve a proportionality assessment.
03What is the permission stage?
Before a claim can proceed, the High Court must grant permission. A judge usually considers the papers, including the claim and the defendant's acknowledgment of service, and asks whether there is an arguable case with a realistic prospect of success, whether the claimant has sufficient interest, and whether the claim is in time. If permission is refused on the papers, the claimant can ask for the decision to be reconsidered at an oral hearing within 7 days.
04What remedies can the court grant?
The main remedies are a quashing order setting the decision aside, a mandatory order requiring action, a prohibiting order preventing unlawful action, a declaration and an injunction. Damages are rarely available. Remedies are discretionary, and the court must refuse relief where it is highly likely that the outcome would not have been substantially different. Since 2022 the court can also suspend a quashing order or limit its retrospective effect.
05Do I need to send a letter before claim?
In most cases, yes. The Pre-Action Protocol for Judicial Review expects claimants to send a letter identifying the decision, the grounds and the remedy sought, and defendants normally respond within 14 days. The protocol does not apply in very urgent cases, and it does not extend the time limit for filing the claim. Ignoring it can lead to costs consequences, and a good letter often resolves the dispute without proceedings.
06Can a business bring a judicial review?
Yes. Companies regularly bring judicial review claims against regulators, licensing authorities, local authorities, HMRC and government departments where a public law decision affects them and no adequate alternative remedy exists. The company must show sufficient interest, act promptly and identify legal errors rather than simply disagreeing with the outcome. Commercial disputes about the performance of a contract with a public body are usually private law matters instead.
Sources and official materials
- Senior Courts Act 1981, section 31 — Application for judicial review, permission and relief
- Civil Procedure Rules Part 54 — Judicial review procedure and time limits
- Pre-Action Protocol for Judicial Review — Letter before claim and response timetable
- Administrative Court Judicial Review Guide — Practice guidance from the Administrative Court
- Judicial Review and Courts Act 2022 — Suspended and prospective quashing orders
- Administrative Court (GOV.UK) — Court information and contacts
General information only, current as at 21 October 2026. It is not legal advice and does not create a solicitor–client relationship. It reflects the law of England and Wales unless stated otherwise; Scotland and Northern Ireland have separate legal systems, and the law changes frequently. Check current official sources and take advice on the facts of your matter.