The letter of claim and pre-action protocols explained
The Letter of Claim is the formal opening document that notifies a defendant they are facing a personal injury claim. It triggers the procedural framework set out in the Civil Procedure Rules’ Pre-Action Protocols — a strict set of rules governing how parties must conduct themselves before issuing court proceedings. Getting the letter of claim right matters: it sets the tone for the negotiation, establishes the procedural deadlines, and creates costs consequences if either side fails to comply. This page explains how letters of claim work in 2026 across the different protocols.
In this guide
- What the Letter of Claim is
- The pre-action protocol framework
- What a good Letter of Claim contains
- Defendant’s response — what should come back
- Consequences of non-compliance
- Settlement at the pre-action stage
- Frequently asked questions
- Related guides
- Our Partner's Fees Explained
- Check If You Could Claim Compensation For Your Injury
Most people who come to us would rather not handle a personal injury claim themselves. Our legal partner runs claims like this on a no win, no fee basis, gathers the evidence, deals with the other side’s insurer, and only takes a fee if your claim succeeds. You can also instruct a solicitor directly free of charge if you would rather, and the law gives you the same rights either way.
What the Letter of Claim is
A Letter of Claim is a formal written notice setting out:
- A clear summary of how the accident happened.
- The basis on which the defendant is alleged to be liable.
- Details of the injuries suffered.
- A summary description of financial losses (with detail to follow).
- The factual basis for the claim being made.
- Identification of any relevant witnesses or evidence.
- A request for the defendant’s response within the protocol time limit.
The Letter of Claim is sent by the claimant’s solicitor to the defendant or — in most cases — directly to the defendant’s insurer once that insurer has been identified.
The pre-action protocol framework
Different protocols apply to different types of PI claim:
Pre-Action Protocol for Personal Injury Claims
The general PI protocol covers claims that aren’t in the specific portals. Key features:
- Letter of claim must include a clear summary of the facts.
- Defendant must acknowledge receipt within 21 days.
- Defendant must investigate and respond within 3 months from acknowledgement.
- Parties should attempt settlement before issuing proceedings.
- Standard form for letter of claim is recommended (Annex A).
Pre-Action Protocol for Low Value Personal Injury Claims in Road Traffic Accidents (RTA Protocol)
For RTA claims under £25,000 (in some cases under £10,000). Most low-value RTA claims now go through the OIC portal, but this protocol still applies in some cases:
- CNF (Claim Notification Form) is the equivalent of a Letter of Claim, submitted electronically.
- Defendant insurer must respond to CNF within 15 days (admit or deny liability).
- Stages and timetables prescribed by the protocol.
Pre-Action Protocol for Low Value Personal Injury (EL/PL) Claims
For employer’s liability and public liability claims under £25,000:
- Electronic CNF.
- Defendant insurer has 30 days for EL claims, 40 days for PL claims.
- Stages 1-3 of the protocol set out structured procedure.
Pre-Action Protocol for Resolution of Clinical Disputes
For clinical negligence claims:
- Letter of Notification optional but recommended.
- Detailed Letter of Claim required.
- NHS Resolution/Trust has 4 months to respond.
- Longer timetable reflects the complexity.
Pre-Action Protocol for Disease and Illness Claims
For industrial diseases (asbestos, NIHL, HAVS, etc.):
- Detailed letter of claim with extensive factual background.
- Defendant has 3 months to investigate and respond.
- Often involves multiple defendants where exposure spanned different employers.
What a good Letter of Claim contains
A well-drafted Letter of Claim addresses all the relevant points clearly and without bluster:
- Identification — claimant’s full name, address, DOB, NI number; defendant’s details; relevant insurance/policy reference if known.
- Account of the accident — when, where, how. Specific enough to be clear; not so detailed as to lock the case down before evidence is gathered.
- Allegations of negligence — specific breaches of duty alleged. For workplace claims, specific Acts and Regulations referenced.
- Injuries claimed — outline of physical and psychological injuries. Detailed medical evidence will follow.
- Special damages — initial summary of financial losses with detail to follow in a Schedule of Loss.
- Disclosure request — request for documents the defendant should disclose at this stage (e.g. accident book entry, risk assessments, CCTV).
- Procedural requests — acknowledgement timeframe, response timeframe, contact details for the solicitor.
Defendant’s response — what should come back
After acknowledging receipt, the defendant (or insurer) must investigate and respond within the protocol time limit. The response should:
- Admit or deny liability (or admit in part).
- Identify the relevant insurer if not already known.
- Provide any documents the defendant agrees to disclose.
- Set out the basis for any denial or partial admission.
- Indicate willingness (or not) to enter ADR or further negotiation.
Consequences of non-compliance
The Pre-Action Protocols are not just procedural niceties — non-compliance has real costs consequences:
- Costs sanctions — courts can order the non-compliant party to pay the other side’s costs at a higher rate, even if they ultimately win.
- Interest on damages — claimants can recover interest from an earlier date where defendants drag out responses.
- Adverse inferences — courts can draw adverse inferences from a defendant’s failure to engage with reasonable requests.
- Strike-out applications — serious procedural breaches can lead to applications to strike out the claim or defence.
For these reasons, both sides typically take the pre-action stage seriously and engage with reasonable timetables.
Settlement at the pre-action stage
Many claims settle at the pre-action stage without proceedings ever being issued. The Letter of Claim and the defendant’s response often define the gap between the parties — and that gap is then negotiated.
Settlements at this stage are typically:
- Faster than full litigation (months rather than years).
- Less expensive (lower costs for both sides).
- Less stressful for claimants.
- Reasonable where liability is fairly clear.
Settlement at this stage is not always best — for complex cases or where the defendant is being unreasonable, proceedings may be necessary to drive a fair outcome.
Frequently asked questions
Can I write my own Letter of Claim?
Technically yes — there is no requirement to have a solicitor. But a solicitor’s Letter of Claim is taken more seriously by defendant insurers, follows the protocol requirements properly, and avoids the procedural pitfalls. Most modern PI claims are conducted through solicitors on no win, no fee.
How long after the accident should the Letter of Claim be sent?
As soon as initial evidence is gathered — typically within a few months of instructing a solicitor. The letter of claim doesn’t need to be perfect or complete — it’s the formal trigger for the protocol process, not the final word on the case. More detail follows during the investigation period.
What if the defendant doesn’t respond at all?
After the protocol deadlines have passed without response, the claimant can issue court proceedings. Failure to engage typically also leads to costs orders against the defendant.
What if the defendant denies liability?
The case can continue with further investigation, gathering of evidence, possible expert reports, and potentially court proceedings to test the liability dispute. A denial isn’t the end of the road — it’s the start of a more substantive phase.
Does the OIC portal use Letters of Claim?
No — the OIC portal uses Claim Notification Forms (CNFs) submitted electronically through the portal. The traditional Letter of Claim doesn’t apply to OIC claims.
Can the Letter of Claim be amended later?
Yes — as evidence emerges, the case may need to be reformulated. Significant changes (e.g. adding a new defendant, alleging different breach of duty) usually require a fresh letter or formal amended particulars.
Does the Letter of Claim have to be in any particular format?
The Pre-Action Protocols provide standard templates (Annex A for general PI). Solicitors typically use template forms but adapt to the specific case. Format flexibility is allowed, but content requirements are not — all the relevant information must be included.
Related guides
- How a personal injury claim works step by step
- What happens when liability is admitted
- Personal injury time limits — the 3-year rule
- The Official Injury Claim (OIC) portal explained
- Do I have a personal injury claim?
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