Critical illness cover: what it pays, what it excludes, and who needs it
Critical illness insurance pays a tax-free lump sum on diagnosis of a defined serious illness — cancer, heart attack, stroke, and others. It is distinct from income protection and life insurance, and serves a different financial purpose. This article explains how it works, what the common exclusions are, and how to decide if you need it.
How critical illness cover works
When you are diagnosed with a condition listed in the policy — typically from a defined list of serious illnesses — the insurer pays a lump sum. Payment is on diagnosis, not on inability to work or death. The money is yours to use as you choose: paying down a mortgage, funding treatment not available on the NHS, adapting your home, or replacing lost income during recovery.
Most policies include a survival period — typically 14 to 30 days after diagnosis — before the benefit is paid. This prevents claims where the policyholder dies immediately after diagnosis before the claim can be processed.
Cancer
Typically the largest claim category — around 60% of CI claims. Definitions vary: most policies exclude early-stage (in situ) cancers and may have minimum severity requirements for some cancer types.
Heart attack
Usually covered subject to a minimum severity threshold based on cardiac enzyme levels or ECG evidence. Check whether your policy uses current diagnostic criteria.
Stroke
Covered with lasting symptoms lasting a defined period (typically 24 hours). Transient ischaemic attacks (TIAs) — mini-strokes with no permanent damage — are generally excluded.
Other conditions
Depending on the policy: kidney failure, major organ transplant, multiple sclerosis, Parkinson's disease, loss of limbs or sight, coronary artery bypass, and more.
Key exclusions to check
- Non-disclosure: Any pre-existing condition not declared at application may be excluded or used to void the policy entirely. See underwriting.
- Severity definitions: Many policies define conditions narrowly. A heart attack must meet specific enzyme or ECG criteria; a cancer claim may be denied if the tumour was classified as in situ. Read definitions carefully, not just the list of covered conditions.
- Self-inflicted conditions: Claims arising from self-inflicted injury, substance abuse, or deliberate exposure to risk are typically excluded.
- Waiting period: Some policies exclude claims for conditions diagnosed within 90 days of the policy start date. See waiting period.
- Policy lapse: If premiums are not paid and the policy lapses, there is no cover. Check whether your policy has a grace period before lapse. See grace period.
Do you need critical illness cover?
Critical illness cover is most valuable for people who: have a mortgage they could not service without income; have dependants; have limited savings; or work in roles where full income replacement during a serious illness is not possible through savings alone. It is also worth considering if you work for yourself and have no employer sick pay — see our guide for the self-employed.
If you already have income protection, critical illness adds a different kind of protection — capital rather than income — which is useful for paying down debt, covering treatment costs, or funding home adaptations. See our comparison guide for a side-by-side analysis, and our stage-of-life insurance guide for where it fits in overall planning.
Critical illness FAQ
Frequently asked questions
- Critical illness cover pays a single lump sum on diagnosis of a specified condition — regardless of whether you can return to work. Income protection pays a regular income for as long as you remain unable to work due to illness or injury. They serve different purposes: critical illness provides capital for debt repayment, adaptations, or treatment; income protection sustains your lifestyle during an extended absence. For people with mortgages and dependants, both are worth considering. See our guide comparing the two and the income protection article.
- Policies vary significantly — from around 30 conditions to over 100 on more comprehensive policies. The ABI publishes guidance on core conditions that member insurers cover. The three conditions that account for the majority of claims are cancer, heart attack, and stroke. More conditions does not automatically mean better cover — check the definitions carefully, particularly for cancer (in situ cancers are often excluded) and heart attack (the severity threshold matters).
- Possibly, but the pre-existing condition will likely be excluded from the policy. Insurers use medical underwriting at application. If you have had a previous heart condition, the policy may cover you for other conditions (cancer, stroke) while excluding heart-related claims. Some conditions may result in a premium loading rather than an outright exclusion. Full disclosure at application is essential — non-disclosure can allow the insurer to void the policy at claim time. See underwriting and pre-existing conditions for how disclosure works.
- Not automatically — critical illness policies pay on diagnosis of a specified condition, not on terminal prognosis. Most standard policies include a terminal illness benefit that pays early if you are diagnosed as terminally ill with less than 12 months to live (this is separate from the critical illness benefit). Life insurance with terminal illness benefit is a different product. If you have both life insurance and critical illness cover, check whether the terminal illness benefit on the life policy would be triggered before the critical illness benefit — you generally cannot claim both for the same diagnosis.