The Citation Verification Rule

The Problem

AI confidently cites cases that don't exist. Lawyers in England and Wales have been ordered to pay wasted costs and referred to their regulators after putting non-existent cases before the court.

Real example: In R (Ayinde) v London Borough of Haringey and Al-Haroun v Qatar National Bank [2025] EWHC 1383 (Admin), judgment of 6 June 2025, the Divisional Court dealt with two cases in which non-existent authorities had been put before the court. It referred a barrister to the Bar Standards Board and solicitors to the Solicitors Regulation Authority. The court said that lawyers who use AI for legal research "have a professional duty therefore to check the accuracy of such research by reference to authoritative sources, before using it in the course of their professional work" (paragraph 7). It listed what a court can do when that duty is not met: public admonition, a costs order, a wasted costs order, striking out, referral to a regulator, contempt proceedings and referral to the police (paragraph 23).

Read the judgment on the National Archives: caselaw.nationalarchives.gov.uk/ewhc/admin/2025/1383.

The Solution

Add this to EVERY prompt involving legal research or citations:

"Provide only citations you can verify. If you cannot verify a citation, say 'UNVERIFIED - please check independently' next to it."

This asks the AI to flag uncertainty instead of inventing a citation. It is not a check. A citation with no flag on it still has to be verified, and so does every other citation in the answer.

The AI responses on this page are made up to show the pattern. No test results have been published for this instruction.

Full Template

[Your research request]

CRITICAL INSTRUCTION:
Provide only citations you can verify with confidence.
If you cannot verify a citation, mark it as "UNVERIFIED - check independently."
Never fabricate case names, citations, or what a case decided.
If you don't know, say you don't know.

Why It Works

An AI model has seen case citations in its training data and has learned their format (e.g., Case v Name [2024] EWCA Civ 123). When asked for a citation, it can produce one that matches the format and does not exist.

Telling the AI to flag citations it cannot verify gives it a way to express doubt. It does not give the AI a way to look the case up, unless the tool you are using searches a source and shows you which.

Example

Without verification instruction:

Find cases on directors' duties in takeover situations.

AI response:

• Re Smith Industries Ltd [2019] EWHC 456 (Ch) - directors must act in shareholders' interests during takeover
• Johnson v ABC Ltd [2021] EWCA Civ 789 - duty to consider all shareholders equally

Problem: These might be fabricated. You won't know until you check (and by then you might have cited them).

With verification instruction:

Find cases on directors' duties in takeover situations.

Provide only citations you can verify. If you cannot verify a citation,
mark it as "UNVERIFIED - check independently."

AI response:

• Re BTR plc [2000] 1 BCLC 740 - UNVERIFIED - check independently (I recall this case discusses directors' duties but cannot verify the exact citation)
• General principle established in Companies Act 2006, s.172 (directors' duty to promote success of company)
• Suggest checking recent High Court decisions on takeovers (I cannot verify specific cases with confidence)

Safer to work from, because the doubtful points are marked. Nothing in the answer has been verified yet.

Verification Process (Even With This Instruction)

ALWAYS verify citations before using them:

1. Check on authoritative sources

   • Find Case Law at caselaw.nationalarchives.gov.uk (free)
   • legislation.gov.uk for statutes (free)
   • BAILII (free)
   • Westlaw UK or LexisNexis, if your firm subscribes

2. Red flags for fake citations

   • Citation format is slightly off
   • Can't find on official databases
   • Court abbreviation doesn't exist
   • Date seems wrong for the proposition
   • Case name sounds "too perfect" for your query

3. If you can't find it

   • Assume it's fabricated
   • Don't use it
   • You can ask the AI where the citation came from, but its answer is not verification. Only the source is

Pro Tips

Add to ChatGPT Custom Instructions:

When providing case citations:
- Only cite cases you can verify
- Mark any uncertain citations as "UNVERIFIED"
- Never fabricate case law
- If you don't know a case, say you don't know

Add to Claude Projects (Legal):

CRITICAL RULE: Never fabricate case citations. If you cite a case,
you must be confident it exists. If unsure, say "I cannot verify
this citation - please check independently."

Use a tool that links to its sources:

• A link lets you open the source and check it
• A link is not proof: read the source to see that it exists and says what the answer says it does
• This site has not published a comparison of tools, so this guide does not recommend one

Common Mistakes

❌ Trusting AI citations without verification: the judgment above lists what a court can do

❌ Only checking some citations: Check EVERY citation, even from normally reliable AI

❌ Assuming "UNVERIFIED" means probably real: It means nobody has checked it. Do not use it until you have found it in an authoritative source

✅ Verify every citation on official databases before using

Quick Reference

Add this to EVERY research prompt:

Provide only verifiable citations.
Mark any uncertain citations as "UNVERIFIED - check independently."
Never fabricate. If you don't know, say you don't know.

Verification checklist:

• Check citation on Westlaw/LexisNexis/BAILII
• Verify case name matches citation
• Verify the decision matches the AI's description
• Verify date and court
• If can't find → assume fake → don't use

Remember: Citing cases that do not exist has led to wasted costs orders and referrals to the SRA and the Bar Standards Board. This isn't theoretical - it's a real professional risk.