Guides Consumer Rights Insurance complaint letter

Insurance Complaint Letter UK — How to Challenge a Rejected Claim

Last reviewed March 2026 — LetterSure editorial team

Had an insurance claim rejected or received a settlement offer that seems unfair? You have the right to challenge it. Here is how to write a formal complaint letter that gets your case reviewed properly.

Can you challenge an insurance decision?

Yes — all regulated insurance companies in the UK must have a formal complaints process. If you believe your claim has been wrongly rejected, your settlement offer is too low, or you have been treated unfairly, you have the right to complain formally and have your case reviewed.

If your complaint is not resolved within 8 weeks you can escalate to the Financial Ombudsman Service — a free, independent service that can require insurers to pay claims, increase settlements, and pay compensation. Their decisions are binding on the insurer.

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Common grounds for an insurance complaint

Claim wrongly rejected

Your claim has been rejected but you believe it falls within your policy cover.

Low settlement offer

Your insurer has offered a settlement significantly below the value of your loss or damage.

Accused of non-disclosure

Your insurer is claiming you failed to disclose information you were not asked about or did not consider relevant.

Unreasonable delays

Your insurer is taking an unreasonably long time to process or settle your claim.

Unfair renewal premium

Your renewal premium has increased significantly without adequate explanation or justification.

Policy cancelled unfairly

Your policy has been cancelled or voided in circumstances you believe are unfair.

What to include in your insurance complaint letter

Your name, address and policy number

Include your full contact details and policy or claim reference number.

What decision you are complaining about

State clearly whether you are challenging a rejected claim, a low settlement, or another issue.

Why you believe the decision is wrong

Set out your grounds clearly and specifically — reference your policy wording where relevant.

Supporting evidence

Photos, receipts, valuations, correspondence, or any other evidence supporting your case.

What outcome you want

A full claim payment, an increased settlement offer, or a review of the decision.

A deadline

Give them 8 weeks to resolve your complaint before you escalate to the Financial Ombudsman.

What happens if your insurer does not resolve your complaint?

If your complaint is not resolved within 8 weeks, or if you receive a final response you are unhappy with, you can refer your case to the Financial Ombudsman Service. You must do this within 6 months of receiving the insurer's final response letter.

The Financial Ombudsman Service is free for consumers and its decisions are binding on the insurer. Keep copies of all correspondence, your policy documents, and any evidence supporting your claim throughout the process.

Example insurance complaint letter structure

Your Name Your Address Policy Number / Claim Reference Date Complaints Department [Insurance Company Name] Address Dear Sir or Madam, Re: Formal Complaint — Policy [XXXXXX] / Claim [XXXXXX] I am writing to formally complain about [describe the decision — rejected claim, low settlement, unfair cancellation, etc.] communicated to me on [date]. I believe this decision is wrong for the following reasons: 1. [State your first ground with evidence] 2. [State your second ground with evidence] I would like [state what you want — claim paid in full, increased settlement, policy reinstated, etc.]. Please respond within 8 weeks. If this complaint is not resolved I will refer it to the Financial Ombudsman Service. Yours faithfully, [Your Name]

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Frequently asked questions

Can I challenge a rejected insurance claim?

Yes. All regulated insurance companies must have a formal complaints process. If you believe your claim was wrongly rejected, complain formally. If not resolved within 8 weeks you can escalate to the Financial Ombudsman Service, which is free and independent.

What are valid grounds for complaining about an insurance decision?

Valid grounds include a claim rejected without valid reason, a settlement lower than the value of your loss, being accused of non-disclosure when you provided accurate information, unreasonable delays, or an unfair renewal premium increase.

How long does an insurer have to respond to a complaint?

Insurance companies must acknowledge your complaint within 5 working days and provide a final response within 8 weeks. If they do not, you can escalate to the Financial Ombudsman Service.

What is the Financial Ombudsman Service?

A free, independent service that resolves disputes between consumers and financial businesses including insurers. If they find in your favour they can require the insurer to pay your claim, increase a settlement, or pay compensation. Their decisions are binding on the insurer.

How long do I have to go to the Financial Ombudsman?

You must refer your complaint within 6 months of receiving your insurer's final response letter. You must normally exhaust the insurer's own complaints process first.

This guide is for general information only. LetterSure letters are personal correspondence drafts and do not constitute legal advice. For legal matters consult a qualified solicitor at solicitors.lawsociety.org.uk.