UK Critical Illness Insurance Claim Denied? How to Appeal

Critical illness insurance is designed to pay a lump sum when you are diagnosed with a serious condition — cancer, heart attack, stroke, and dozens of others. The payout is tax-free and can be used however you choose: to replace lost income, pay off your mortgage, fund private treatment, or adapt your home.

Yet critical illness claims are denied at a higher rate than almost any other insurance product in the UK. Insurers rely on narrow medical definitions, non-disclosure disputes, and policy exclusions to refuse payments — often when policyholders are at their most vulnerable.

If your CI claim has been refused, this guide explains your rights and how to fight back.

Why UK Critical Illness Claims Are Denied

Condition Does Not Meet the Policy Definition

This is the most common reason. Critical illness policies define each covered condition very precisely. For example:

• Cancer: Policies often exclude early-stage or in-situ cancers, cancers with a low Malignancy Grade, or skin cancers other than malignant melanoma. If your cancer diagnosis falls outside the policy's definition, the claim is denied.
• Heart attack: Policies typically require a specific rise in cardiac enzymes (troponin) and/or ECG changes. A heart attack that doesn't meet these precise clinical criteria may be excluded.
• Stroke: Permanent neurological deficit lasting a defined period (often 24 hours) is required by most policies. Transient ischaemic attacks (TIAs) are usually excluded.

Non-Disclosure

If the insurer believes you did not accurately disclose your medical history at application, it may deny the claim and potentially void your policy entirely. This includes failure to disclose smoking status, pre-existing conditions, or previous diagnoses — even if you believed them to be irrelevant.

Surviving Period Not Met

Many CI policies require you to survive for a minimum period after diagnosis (typically 10 to 14 days) before a claim is payable. If the policyholder dies within the survival period, the CI claim is denied (though a life insurance claim may still be valid).

Excluded Conditions or Circumstances

Some policies exclude conditions that result from self-inflicted injury, alcohol or substance abuse, or conditions diagnosed within a deferment period after policy inception.

Your Rights Under FCA Regulation

Your critical illness insurer is regulated by the FCA and must follow the FCA's DISP complaint handling rules. This means:

• They must acknowledge your complaint within five business days
• They must issue a final response within eight weeks
• If unresolved, you can refer to the Financial Ombudsman Service (FOS) within six months of their final response

The FOS has the authority to overturn CI claim denials, including those based on disputed medical definitions and non-disclosure allegations.

Step-by-Step: Challenging a Denied CI Claim

1. Obtain the Denial Letter and Policy Wording

Ask for the denial in writing if you have not already received it. Read both the denial letter and the full policy wording carefully, focusing on:

• The exact definition of your diagnosed condition
• The specific clause or provision used to deny the claim
• The non-disclosure provisions and what they require

2. Gather Medical Evidence

Your consultant should provide a written report confirming:

• The precise diagnosis and classification
• The clinical criteria met (e.g., troponin levels for heart attack, cancer staging)
• The date of diagnosis and clinical course

Where the insurer's definition is ambiguous, medical evidence that your diagnosis meets the plain meaning of the condition — even if not the technical definition — is valuable.

3. Submit a Formal Complaint

Write a formal complaint to the insurer's complaints department. Reference the specific policy wording and explain, with clinical evidence, why your diagnosis meets the covered condition definition.

If the denial involves non-disclosure, gather medical records to demonstrate:

• You had no prior diagnosis, treatment, or symptoms of the relevant condition before applying
• The insurer's questions were ambiguous or did not clearly request the information they claim was omitted

4. Escalate to the FOS

If the complaint does not resolve the matter, refer to the FOS. The FOS takes a consumer-friendly approach to CI disputes, particularly where:

• Policy definitions are unclear or technical
• The insurer's non-disclosure allegation is disproportionate to the omission
• The medical evidence clearly supports the claim

Important: ABI Code of Practice

The Association of British Insurers (ABI) publishes a code of practice on critical illness cover requiring clear, plain-English definitions and proportionate non-disclosure handling. If your insurer is an ABI member and has not followed the code, reference this in your complaint.

Fight Back With ClaimBack

ClaimBack helps UK policyholders challenge denied critical illness claims with tailored appeal letters that address medical definitions, policy wording disputes, and non-disclosure allegations. We know how insurers argue — and how to counter them.

Start your critical illness appeal with ClaimBack

Related Reading

• How to Write an Insurance Appeal Letter
• Common Reasons Insurance Claims Are Denied
• How to Use the Insurance Ombudsman