Aviva Insurance Claim Denied? How to Fight Back in the UK

Aviva is one of the UK's largest composite insurers, covering millions of policyholders across health, life, income protection, critical illness, and general insurance. If Aviva has denied your claim, you have well-defined rights to challenge that decision under FCA regulations, and free independent services are available to help you. The Financial Ombudsman Service (FOS) resolved tens of thousands of insurance complaints in favour of consumers last year — many of them against major insurers. This guide walks you through the full appeal process.

Why Insurers Deny Aviva Claims

Aviva claim denials vary significantly by product type, and understanding which applies is essential to building the right appeal.

Health insurance denials. Aviva's private medical insurance (PMI) most commonly denies claims on the basis of pre-existing conditions (under moratorium or full medical underwriting exclusions), failure to obtain pre-authorisation for planned treatment, treatment delivered by a non-recognised provider, treatment not included in your selected cover level, or a clinical assessment that the treatment is not medically necessary. The FCA's ICOBS 8 rules require Aviva to handle claims fairly and to have adequate claims processes.

Life insurance denials. The most common life insurance denial ground is non-disclosure of material information at the time of application — undisclosed medical history, smoking status, or hazardous occupation. Aviva must prove that the non-disclosed information was genuinely material (i.e., that it would have affected their underwriting decision) under the Insurance Act 2015. If the information is immaterial to the cause of death, Aviva generally cannot rely on it to deny the claim. Suicide exclusions in the first 12 months and exclusions for specific activities also arise.

Income protection and critical illness denials. Critical illness cover is highly specific: the condition must meet the exact definition in the policy, including severity criteria. A diagnosis of the correct condition at an insufficient severity level will typically be declined. Income protection disputes frequently involve the definition of disability — whether you are incapable of your "own occupation" or "any occupation" — and whether the deferral period has elapsed.

Non-disclosure disputes across all products. The Insurance Act 2015 replaced the Marine Insurance Act 1906's "utmost good faith" standard and now requires Aviva to show that any non-disclosure was a "qualifying misrepresentation" (deliberate, reckless, or careless). Even careless non-disclosures now entitle Aviva only to a proportionate remedy — not necessarily full denial — based on what they would have done had they known the true facts.

How to Appeal an Aviva Claim Denial

Step 1: Get the Denial in Writing

Request a full written explanation of Aviva's decision, citing the specific policy clause relied upon. If you received only a verbal explanation, write to Aviva requesting their decision in writing. This document is the foundation of your appeal. Aviva is required under ICOBS 8 to communicate claim decisions clearly.

Step 2: Review Your Policy Documents Carefully

Read your policy schedule, terms and conditions, and any endorsements or exclusions. For critical illness cover, compare the exact policy definition of the covered condition against your medical evidence. For non-disclosure disputes, assess whether the undisclosed information was material and whether Aviva's remedy is proportionate under the Insurance Act 2015.

Step 3: Gather Medical and Supporting Evidence

Obtain detailed letters from your treating specialists. For critical illness claims, you need documentation demonstrating that the severity criteria in the policy definition are met. For income protection claims, gather functional assessment reports and occupational health evidence. For non-disclosure disputes, compile your GP records to establish what was known at the time of application.

Step 4: File a Formal Complaint with Aviva

Submit a formal written complaint to Aviva's complaints team. Under FCA rules (DISP 1), Aviva must:

• Acknowledge your complaint within 3 business days
• Resolve it within 8 weeks
• Issue a Final Response Letter if they cannot resolve it sooner

Send to: Aviva Customer Complaints, PO Box 7684, Peterborough, PE3 8DD, or submit online via aviva.co.uk. Send by recorded post if writing physically. Address each denial ground specifically in your complaint letter.

Step 5: Escalate to the Financial Ombudsman Service (FOS)

If Aviva's Final Response Letter upholds the denial, or if 8 weeks pass without resolution, escalate to the Financial Ombudsman Service:

• Online: financial-ombudsman.org.uk
• Phone: 0800 023 4567 (free from UK landlines)
• Email: complaint.info@financial-ombudsman.org.uk

The FOS is free to consumers, independent, and its decisions are binding on Aviva under the Financial Services and Markets Act 2000. Ombudsman decisions in insurance cases favour consumers in a significant proportion of cases involving critical illness and income protection disputes.

Step 6: Consider FCA Regulatory Complaint

If you believe Aviva's conduct is part of a systemic pattern, file a regulatory complaint with the FCA at fca.org.uk. The FCA cannot resolve individual disputes but can investigate firms for systemic TCF (Treating Customers Fairly) failures.

What to Include in Your Appeal

• Written denial letter from Aviva identifying the specific policy clause relied upon
• Full policy schedule and terms and conditions, with the relevant provisions highlighted
• Specialist medical letters addressing the denial reason directly, including severity criteria for critical illness claims
• GP records relevant to non-disclosure disputes, demonstrating what was known at the time of application
• A clear written argument responding to each denial ground, citing the Insurance Act 2015 where relevant

Fight Back With ClaimBack

Aviva critical illness and income protection denials are among the most technically complex in UK insurance — the policy definitions are precise, and the evidence requirements are specific. A formal FOS complaint citing the Insurance Act 2015 and ICOBS 8 puts Aviva under meaningful regulatory scrutiny and has a strong track record of reversing incorrect denials. ClaimBack generates a professional appeal letter in 3 minutes.

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Related Reading

• How to Write an Insurance Appeal Letter
• What Is Medical Necessity?
• Internal vs External Insurance Appeal