Seven signs you're dealing with a real vexatious litigant

There’s an old proverb: you can win over a wise man with reason, but you can’t convince a fool with proof.

Litigants in person (LiPs) are on the rise, driven in part by the increasingly unaffordable cost of representation. The AI revolution has also armed even the least experienced would-be litigator with a seemingly inexhaustible arsenal of legal tools, available at little or no cost.

And with more LiPs, come the vexatious litigators.

Take the recent example of Attorney General v Ms Sandra Messi [2026] EAT 34. Since 2017, Ms Messi had filed more than 50 Employment Tribunal claims, commonly alleging discrimination, whistleblowing detriment or unpaid wages. None of them succeeded. Many were struck out, dismissed following non-attendance or withdrawn. She is now subject to an indefinite restriction of proceedings order.

That is good news in one sense. More troubling is that it took over 50 claims before the judiciary intervened.

The brave new AI-driven world will increasingly require parties to manage vexatious litigation rather than simply wait for the courts to stop them. Separating a genuinely vexatious litigant from a particularly dogmatic or determined adversary is, at least in the early stages, an increasingly important skill.

Here are seven clues that you may be dealing with a genuine vexatious litigant.

1. They refer to lawyers who don’t exist. A common trope is to suggest that everything the vexatious litigant does is based on legal advice, sometimes referring directly to “my solicitor” or “counsel”, but rarely naming them. Ask, neutrally, who is acting and whether correspondence should be directed to that person.

   
   

2. They mirror every allegation. Whatever charge is made against them — harassment, defamation, unreasonable conduct — is immediately thrown back, often in identical language. It is like shouting into an echo chamber. The vexatious litigant is perfectly at home trading allegations. Don’t let it spiral – return to the evidence.

   
   

3. They make excessive and uncritical use of AI. Lawyers can be just as guilty of overreliance on AI as anyone else, so polished drafting alone proves very little. The vexatious litigant will, however, use AI uncritically, often cutting and pasting directly from the chat without checking. Don’t assume authorities are real, but try to avoid corresponding with a computer. AI prefers verifying over objective analysis because agreeing with the user is less resource demanding. Close down the discussion early and concentrate on the end goal.

   
   

4. They make constant data-protection complaints. Why? Because the process is generally cost and risk free and imposes real-time burdens on the other party, especially if they are a data controller. Data controllers must deal properly with subject access requests and, from 19 June 2026, must also operate a process for handling data-protection complaints. The vexatious litigant is attracted to regulated environments because the personal cost of being wrong is low, and the reward for a stern word from the ICO is complete vindication. Respond calmly and make sure every letter is one the regulator would approve of, but don’t be afraid of the complaint: at least you’re now dealing with something that has an end process.

   
   

5. They target individuals. Another familiar tactic is to make matters personal. Rather than concentrating on the more obvious corporate responsibility, the vexatious litigant pursues individual officers, employees or advisers and tries to construct personal liability, however misconceived. Do not rise to it, but protect your staff and partners. Centralise communications, use role-based contact details where appropriate and avoid personal mudslinging. If at all possible, don’t allow the vexatious litigant to deal with the same person continually: doing so can be draining and damaging.

   
   

6. They are utterly relentless. The vexatious litigant will not take no for an answer, and whatever ending you thought you had designed will rarely be the end. Expect the matter to continue. Hunker down. You’re in for the long game. Use tactics such as strike-out applications sparingly; sometimes a definitive determination is more valuable than a technical victory. Do not send correspondence merely for correspondence’s sake, and consider shutting communications down. Silence is often the best weapon against those who shout the loudest.

   
   

7. They use multiple forums. Expect the fight on multiple fronts: regulators, courts, tribunals, complaints procedures, social media, the police, local authorities, MPs, websites and ombudsmen. Every forum is another stage and an opportunity for the vexatious litigant to perform. What the vexatious litigant is looking for is validation from someone, anyone, in a position of perceived authority. Complaints are part of a recruitment campaign; the vexatious litigant is looking for allies at every opportunity. Shut each complaint down dispassionately and objectively. Log everything. Chronologies are invaluable; keep them as you go. Retain control of the narrative by remaining on the high moral ground: don’t lower yourself to the vexatious litigant’s level.

   
   

Overall, be prepared to put the time in. You cannot “beat” a genuinely vexatious litigant in the sense of persuading them to give up and move on, any more than you can change the weather. But you can narrow the playing field. The vexatious litigant is more interested in the fight itself, and will often sacrifice long-term strategy for short-term dopamine. Do not rise to it. They want an audience; don't provide one.

No matter how tempting it is to respond, no matter how provocative the vexatious litigant becomes, remember: if you’re arguing, they’re winning.