Insurance claim denied? How to appeal it, step by step

Find the exact reason, check it against your policy wording, write an appeal they have to answer, and take it to the free ombudsman or external review if they still say no.

Updated 30 October 2026 · 4 min read

A denial letter feels final. It usually is not. Insurers turn down claims for reasons that do not survive a careful read of the policy, and every major market has a free route to challenge the decision. What wins is not anger or a long letter. It is answering their exact reason with their own policy wording and your evidence.

1. Find the exact reason

Read the denial letter for three things:

The reason they give, in their words: "gradual damage", "wear and tear", "not disclosed", "reported late", "excluded under section 4.2".
The clause or section of the policy they rely on.
The deadline for an appeal or complaint, if they give one.

If the letter is vague ("your claim does not meet the policy terms"), write back and ask which clause they are relying on and what evidence they used. You cannot answer a reason you have to guess.

2. Get the full policy wording

The summary or schedule you were sent when you bought the policy is not enough. Ask for the full policy wording that applied on the date of the loss, including definitions. Then read the clause they quoted next to the definitions. Many denials fall apart here: the clause says "gradual leak over a period of weeks", and your plumber's report says the pipe burst overnight.

3. Match the reason to a counter

What they say	What usually answers it
Wear and tear, or gradual damage	Evidence it was sudden: a repair report, dated photos, when it was last seen working or dry
Not covered or excluded	The exact wording of the exclusion, read with the definitions. Exclusions are read narrowly
You did not tell us something	The exact question you were asked, your answer, and whether it had anything to do with this loss
Reported too late	When you first told them, and whether the delay actually harmed their ability to assess the claim
Not enough evidence	A list of what you have sent, and an offer to provide anything specific they name
Underpaid	Their calculation line by line, set against quotes, receipts or the policy limits

4. Write the appeal

Keep it to one page. Insurers are processing a file, and a short, structured letter is easier to say yes to.

Subject line with your claim number, policy number and the date of their decision.
One line saying you are making a formal complaint about the decision.
Their reason in their words, and the clause.
Your answer, with the evidence attached and named.
One clear ask: pay the claim in full, or reconsider and send the evidence they relied on.
A date for their reply.

Here is an example:

Subject: Claim NH-C-55102: complaint about the decision of 3 April 2026, policy NH-220817

I am making a formal complaint about your decision of 3 April 2026 to decline claim NH-C-55102 for water damage to my kitchen ceiling.

You say the damage was caused by a gradual leak, excluded under section 4.2. The plumber who attended on 29 March recorded a sudden failure of a joint under the bathroom basin, and the ceiling was dry on 27 March. His invoice and letter are attached.

Please confirm cover for the repair quote of £4,860, or send me the evidence you relied on to find a gradual leak, by 1 May 2026.

Send it by email or the insurer's complaints form, and keep a copy with the date.

5. If they still say no

UK. The insurer has up to eight weeks to send a final response. If you are unhappy with it, or eight weeks pass with no answer, take the complaint to the Financial Ombudsman Service. It is free, and you must go to it within six months of the date on the final response.

US, health insurance. You have 180 days from the denial notice to file an internal appeal. The plan must decide within 30 days if you have not had the treatment yet, or 60 days if you have, and much faster when it is urgent. If the denial stands, you can ask for an independent external review within four months of the final decision. External review is free or costs very little, and the insurer no longer has the final say.

US, home, car and other insurance. Appeal inside the insurer first, then file a complaint with your state's department of insurance. It is free, and insurers have to respond to it.

Elsewhere. Most countries have a free, independent body for insurance complaints. In Ireland it is the Financial Services and Pensions Ombudsman, in Australia the Australian Financial Complaints Authority, in Canada the General Insurance OmbudService or the OmbudService for Life and Health Insurance, and in France La Médiation de l'Assurance. Your insurer's final letter should name the right one.

Keep a simple file

A one-page record makes every step faster: the claim and policy numbers, the dates of the loss, of your claim and of their decision, what you sent and when, and the deadline you are working to. If the case reaches an ombudsman, that file is half the work.

The short version

Get their exact reason and clause. Read it against the full policy wording. Answer that reason, and only that reason, with evidence, in one page with one ask and a date. If they still refuse, the ombudsman or external review is free and independent.

Insurance claim denied? How to appeal it, step by step — Save this guide

Questions

Should I accept a reduced offer?

Only once you know how they worked it out. Ask for the calculation in writing, line by line. If a line does not match your policy or your evidence, challenge that line. Accepting a final settlement can close the claim, so read the wording before you agree.

Do I need a lawyer to appeal?

Not for most claims. The insurer's appeal process and the UK Financial Ombudsman Service are free, US external review is free or close to it, and all are designed for people to use on their own. For a very large claim, a court date or a dispute about injury, get proper advice.

They say I did not tell them something when I took out the policy. Can they refuse to pay?

It depends on what you were asked and whether the mistake was honest, careless or deliberate. In the UK, an honest and reasonable answer does not let them refuse, and a careless mistake often only reduces what they pay, depending on what they would have done had they known. Ask them to show you the exact question and your answer.

How long does the insurer have to reply to my appeal?

In the UK, up to eight weeks for a final response to a complaint. For US health plans, 30 days if the treatment has not happened yet and 60 days if it has, and much faster for urgent care.

General information, not legal advice. Rules change and depend on where you live: check the official source before you rely on a date or an amount.