How to Complain to the Financial Ombudsman Service About Insurance

If you have been treated unfairly by an insurance company in the UK and cannot resolve the dispute directly, the Financial Ombudsman Service (FOS) is your most powerful free resource. The FOS independently investigates complaints against financial services firms — including insurers — and can compel them to pay claims, reverse decisions, and compensate you for financial loss and distress.

This guide explains exactly how the FOS process works, who can use it, and how to give your case the best possible chance of success.

What Is the Financial Ombudsman Service?

The FOS was established by Parliament under the Financial Services and Markets Act 2000. It is a free, independent dispute resolution service for consumers and small businesses. Over a million complaints are received by the FOS each year, with insurance disputes accounting for a substantial proportion.

The FOS can handle complaints about:

• Private medical insurance (PMI)
• Life insurance and critical illness cover
• Income protection insurance
• Travel insurance
• Car and home insurance
• Payment protection insurance (PPI)
• Any other FCA-regulated insurance product

The FOS cannot handle complaints about NHS treatment, workplace disputes, or insurance policies not regulated by the FCA (e.g., some international expatriate policies written outside the UK).

Who Can Use the FOS?

You can refer a complaint to the FOS if you are:

• An individual consumer
• A small business with fewer than 50 employees and an annual turnover of under £6.5 million
• A charity with annual income under £6.5 million
• A trustee of a small trust with net assets under £5 million

You must have already made a formal complaint to the insurer before referring to the FOS.

The FCA's Eight-Week Rule

Before you can go to the FOS, you must first complain to the insurer directly. The insurer then has eight weeks to issue a final response. Only after one of the following conditions is met can you refer to the FOS:

1. The insurer issues a final response that you are unhappy with
2. Eight weeks pass without a final response

Once either condition is met, you have six months to refer to the FOS. This deadline is firm — missing it will usually prevent the FOS from considering your case.

How to Submit a Complaint to the FOS

Step 1: Try to Resolve It with the Insurer First

Submit a formal complaint to your insurer in writing. Note the date. Keep copies of all correspondence.

Step 2: Check You Are Within Time

Confirm:

• You have received a final response letter from the insurer, or eight weeks have passed
• You are within six months of the final response date
• The policy is FCA-regulated

Step 3: Complete the FOS Online Complaint Form

Go to financial-ombudsman.org.uk and complete the online complaint form. You will need:

• The insurer's name and your policy number
• A summary of what happened and why you think the insurer was wrong
• The insurer's final response letter
• Supporting documents: your policy, denial letters, medical evidence, correspondence

Alternatively, you can call the FOS on 0800 023 4567 (free) or submit by post.

Step 4: Case Handler Review

A case handler will be assigned to your complaint. They will:

• Contact you and the insurer for information
• Review all evidence
• Issue a preliminary view — their assessment of the case

You and the insurer can both accept or reject the preliminary view.

Step 5: Ombudsman Final Decision

If either party rejects the preliminary view, an ombudsman reviews the case and issues a final decision. This decision is:

• Binding on the insurer if you accept it
• Not binding if you reject it (though you may then need to consider legal action)

You do not have to accept an ombudsman decision if it is not in your favour — you are free to pursue court action instead.

What Can the FOS Award?

The FOS can direct an insurer to:

• Pay the full amount of your denied claim
• Pay interest on amounts owed
• Pay compensation for distress and inconvenience (typically £100–£750 for moderate cases; more for serious cases)
• Cover your reasonable costs arising from the denial

The maximum award is currently £415,000 per complaint (for complaints referred after 1 April 2024).

Tips for a Strong FOS Complaint

Be specific. Reference the exact policy wording the insurer relied upon and explain precisely why their interpretation is wrong.

Provide strong medical evidence. For health insurance disputes, a letter from your GP or consultant stating the treatment was medically necessary carries significant weight.

Cite the IPID. The Insurance Product Information Document given to you at inception sets out key terms. If the insurer's denial contradicts what the IPID said, make this clear.

Document every communication. Keep a log of calls, emails, and letters. Note the names of staff you spoke with and the date of each conversation.

Use clinical guidelines. If your treatment is supported by NICE guidelines or other UK clinical standards, reference these in your submission.

Fight Back With ClaimBack

ClaimBack helps UK policyholders prepare FOS-ready complaint submissions with professional appeal letters, evidence frameworks, and insurer-specific arguments. We help you navigate the FOS process from start to finish.

Start your FOS complaint preparation with ClaimBack

Related Reading

• How to Write an Insurance Appeal Letter
• Internal vs External Insurance Appeal: What's the Difference?
• Common Reasons Insurance Claims Are Denied