Aviva Health Insurance Denied in the UK: Appeal

Aviva is one of the UK's largest private medical insurance providers, offering individual and group health plans to millions of policyholders. Despite its size and reputation, Aviva denies a significant number of health insurance claims each year — and many of those denials can be successfully challenged. If Aviva has refused to pay your claim, here is how to fight back.

About Aviva Health Insurance

Aviva's health insurance products include the Aviva Health Plan, which offers modular cover across hospital treatment, mental health, cancer care, and diagnostics. Aviva also markets DigiCare+, a digital health app offering annual health checks, mental health support, and access to online GP consultations. DigiCare+ is increasingly bundled with health plans, which creates a new source of disputes around what is covered digitally versus in-person.

Aviva offers both moratorium underwriting (where pre-existing conditions are automatically excluded for a period) and full medical underwriting (where conditions are declared upfront and specifically excluded or included). The type of underwriting on your policy directly affects what can be denied.

Common Reasons Aviva Denies Claims

Pre-existing condition exclusions under moratorium underwriting. Aviva's standard moratorium underwriting excludes conditions that you had symptoms for, sought advice about, or received treatment for in the five years before the policy started. If you are diagnosed with a condition during the policy period but had any prior symptoms, Aviva may deny the claim as pre-existing.

Treatment not recognised as medically necessary. Aviva employs clinical assessors who review claims against its internal clinical guidelines. A consultant's recommendation does not automatically override Aviva's internal assessment. However, Aviva's guidelines themselves can be challenged.

Outpatient mental health limits. Aviva's mental health cover — even at higher tiers — typically has session limits for talking therapies. Once you hit the limit, claims are denied. Check your Schedule of Benefits for the exact cap.

Cancer drug restrictions. Aviva covers NICE-approved cancer drugs, but coverage of drugs outside NICE guidelines (or where NICE guidance is pending) may be refused. This is a significant source of distress for cancer patients.

DigiCare+ disputes. Some policyholders have found that Aviva directs them to DigiCare+ services when they request in-person referrals, effectively gatekeeping access. If Aviva has refused to authorise in-person treatment on the basis that DigiCare+ can provide the service, this is worth challenging — particularly for conditions requiring physical examination or ongoing specialist care.

Specialist not on Aviva's list. Aviva maintains a list of recognised consultants and specialist hospitals. If your consultant is not recognised by Aviva — even if they practice at a recognised hospital — your claim may be shortfalled or denied.

Aviva's Internal Complaint Process

Aviva is regulated by both the FCA and the Prudential Regulation Authority (PRA). It must follow the FCA's rules on complaint handling, which include:

• Acknowledging your complaint within five business days.
• Issuing a final response within eight weeks.
• Providing information about the FOS in any final response.

To make a formal complaint:

1. Write to Aviva's Customer Relations team at: Aviva Health, PO Box 3553, Norwich, NR1 3DA (check Aviva's current address on their website as this may change).
2. Reference your policy number, claim number, and the date of the denial.
3. Enclose copies of your denial letter, your GP referral, and any consultant letters.
4. State clearly what you want Aviva to do — pay the claim, provide a clinical review, or explain the policy clause in full.

Requesting a Clinical Review

Aviva offers a clinical review process where a senior clinical assessor reviews the original decision. This is separate from the formal complaints process and can be faster. Ask specifically for a "clinical review" rather than just filing a complaint. The two processes can run in parallel.

If the clinical review upholds the denial, you can still pursue the formal complaint and then the FOS.

Escalating to the Financial Ombudsman Service

The Financial Ombudsman Service (FOS) is a free, independent service for resolving disputes between consumers and UK financial services firms. After eight weeks (or after Aviva issues a final response), you can refer your case to the FOS at no cost.

The FOS will:

• Request the full file from Aviva, including internal notes and the clinical evidence used to deny your claim.
• Appoint an adjudicator to assess the case.
• Issue a provisional decision, to which both you and Aviva can respond.
• Issue a final decision, which is binding on Aviva if you accept it.

The FOS regularly finds in favour of consumers in health insurance disputes, particularly where pre-existing condition determinations are unclear or where "medical necessity" language has been applied inconsistently.

Tips for a Stronger Appeal

• Get a second consultant opinion. If Aviva says the treatment is not medically necessary, a letter from a second independent consultant supports your case significantly.
• Reference the policy schedule directly. Quote the exact benefit section that you believe covers the treatment. Do not let Aviva's denial rely on a vague reference to "clinical guidelines" without identifying the specific guideline.
• Document the impact. The FOS considers consumer detriment. A letter explaining the practical harm of the denial — delays to treatment, pain, inability to work — is relevant evidence.
• Check your employer scheme terms. If Aviva is your employer's group PMI provider, your HR team may have access to a dedicated scheme manager at Aviva who can resolve the issue directly.

Aviva is a well-resourced insurer with experienced claims assessors. But the FOS process levels the playing field, and a well-documented appeal regularly overturns Aviva's initial decisions.

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Related Reading:

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