The difference between critical illness cover and terminal illness cover is the event that triggers the payment. Critical illness cover pays when you are diagnosed with a condition on the policy's list and the policy's definition of it is met; terminal illness cover, often called terminal illness benefit, pays when a consultant expects an illness to lead to death within 12 months. In the Legal & General, Aviva and Royal London policies quoted on this page, terminal illness cover comes with the life cover, and Aviva's standalone critical illness plan also counts terminal illness as one of its critical illnesses.

Marie Curie gives free, trusted information on terminal illness, dying and bereavement, online, in print and by phone, whether the diagnosis is yours or belongs to someone close to you. Its Support Line is 0800 090 2309, free from landlines and mobiles, open 8am to 6pm Monday to Friday and 10am to 4pm at weekends.

What follows sets the two side by side, using the wording that Legal & General, Aviva and Royal London print in their own documents.

What does each one pay for?

Both pay a lump sum while the person insured is alive, which is why the two are often muddled. They answer different questions, though: one asks whether you have a named condition, the other asks how long a consultant expects you to live.

Critical illness coverTerminal illness cover
What triggers a paymentA diagnosis, or in some cases a medical procedure, that meets a definition on the insurer's listA consultant's opinion that the illness is expected to lead to death within 12 months (Royal London: 12 months or less to live)
Time test after the eventA survival period: 14 days at Legal & General, at least 10 days at Aviva, 30 days at Royal LondonThe life-expectancy test itself, set out in the policy definition
Where it sitsBought on top of, or beside, life cover: a separate policy at Legal & General, a standalone Critical Illness Plan at Aviva, an optional extra at Royal LondonPart of the life cover at all three; Aviva's Critical Illness Plan also lists it as a critical illness
After a claim is paidLegal & General's critical illness policy ends; Aviva's Critical Illness Plan ends; Royal London's Serious Illness Benefit ends but its Life Cover continuesThe life policy ends (and at Royal London the Serious Illness Benefit ends too)

The Association of British Insurers (ABI) reserves the name "critical illness cover" for insurance that pays when the person insured meets a policy's definition of a specified critical illness, and cancer, heart attack and stroke must always be among them. None of that turns on how long someone is expected to live. How the whole product compares with an ordinary life policy is set out in life insurance compared with critical illness cover, and life and critical illness cover explains how the two are put together in one plan.

How do insurers word critical illness cover?

Legal & General's critical illness terms (QGI14872, October 2026) say: "Critical Illness Cover will pay you the amount of cover if you are diagnosed with a condition or undergo a medical procedure as listed in Critical Illness Cover Definitions. Your policy will then end." The diagnosis must come from a UK consultant "whose specialism we consider appropriate to the relevant condition", and the person insured must survive for 14 days from diagnosis, even if the policy ends in that time.

Aviva sells critical illness cover direct as a Critical Illness Plan of its own. The plan's policy summary (DA09001, May 2023) says it pays if, during the policy term, you are diagnosed with a critical illness that meets Aviva's policy definition and you survive for at least 10 days. It covers only the illnesses its policy defines, and it does not pay out if you die.

Royal London's direct terms (code D2C TTC 1223139355) call the optional cover Serious Illness Benefit. It covers six illnesses, among them cancer, heart attack, stroke and dementia, each with conditions attached, and the terms say: "Having one of these conditions doesn’t mean we’ll automatically pay a claim." The person insured must survive 30 days from the date the medical definition is met.

So a listed name is only the start; the definition behind it decides the claim. Every policy's cancer, heart attack and stroke wording has to match or improve on the ABI's model wordings, which the ABI minimum standards page explains. Each insurer then writes its own list, as how critical illness cover works shows.

Should you want the definitions on a quote checked against your own medical past, a broker, FCA-authorised, can ring you free of charge to weigh each wording with you once your details are in this page's form.

What has to be true for terminal illness cover to pay?

Terminal illness cover rests on a medical opinion about life expectancy, not on a named condition. Legal & General's life insurance terms (QGI12849, October 2026) define it this way:

Terminal illness is defined as a definite diagnosis by your hospital consultant of an illness that satisfies both of the following:

The illness either has no known cure or has progressed to the point where it cannot be cured; and

In the opinion of your hospital consultant and our Medical Officer (a qualified doctor employed by Legal & General), the illness is expected to lead to death within 12 months.

Legal & General treats the payment as an early payment of the death benefit, calculated on the date the definition is met, and warns that it may be less than would have been paid at death. The policy then ends, so nothing further is paid when the person dies.

Aviva uses one two-part definition in two places: the conditions for its Life Insurance Plan (DA03011, May 2023) and those for its Critical Illness Plan (DA09002, May 2023). In both, the opinion that the illness is expected to lead to death within 12 months is the attending consultant's, with no insurer's doctor named in the definition. Royal London's direct terms frame the test as the treating consultant's view that you have no more than a year to live, and its Chief Medical Officer has to accept that view before a claim is paid.

The ABI's guide does not set a model wording for this. It records that the definition of "terminal illness" was deleted from the guide "as this was seldom used in critical illness cover", and that insurers "can still choose to include a terminal illness definition in their policies." The fuller picture of definitions, claims and payouts is in terminal illness benefit in life insurance.

If you have a terminal illness, will critical illness cover pay out?

It depends on what the policy lists. Aviva's Critical Illness Plan conditions include "Terminal illness – where death is expected within 12 months" among the critical illnesses the plan covers, so a diagnosis meeting that definition can be claimed under the plan itself. Royal London's Serious Illness Benefit names six illnesses and terminal illness is not one of them; there, as at Legal & General, terminal illness cover belongs to the life policy.

Beyond that, a critical illness claim turns on the condition and its definition rather than on the prognosis. Because the two definitions are separate, one diagnosis may meet both, or only one; which it meets is decided on the policy wording and the medical evidence.

How a claim under one benefit would sit with the other on a policy you already hold is something the broker can go through with you on the call-back, at no cost, and your policy schedule shows which benefits you have.

What happens after a claim differs by insurer. Aviva's Critical Illness Plan pays the full cover amount once and then ends. Legal & General's critical illness cover is a separate policy that ends when a claim is accepted, while its terminal illness cover belongs to the life policy. At Royal London, paying the Serious Illness Payout ends only the Serious Illness Benefit, and the terms say "Your Life Cover will continue", whereas paying a terminal illness claim ends the policy and the Serious Illness Benefit with it.

For cover that pays when the policyholder dies, rather than on a diagnosis, see whether critical illness cover pays out if you die, or browse the other critical illness and income guides.

Where does each sit in a policy, and what about the end of the term?

Terminal illness cover is built into the life cover. Royal London's terms say its policy pays a single cash sum if you die or are diagnosed with a terminal illness before the end of the policy term, and Legal & General's summary lists terminal illness cover as "included with Life Insurance". Aviva's Life Insurance Plan summary (DA03008, May 2023) says that plan provides life cover and terminal illness cover. Critical illness cover is the part you choose: Royal London says you "pay extra each month" for Serious Illness Benefit, while Legal & General and Aviva each sell critical illness cover as a policy in its own right. The exact terms and any price will be in your quote and your policy schedule.

In the current documents quoted here, both benefits are tied to the policy term: the diagnosis has to come while the policy is in force. Legal & General's summary (QGI14786, October 2026) adds that terminal illness cover cannot be claimed if the policy runs for less than two years. Older policies were not always worded this way, and the guide to terminal illness benefit looks at a cut-off before the end date that one older policy carried.

If it would help to talk through which of the two matters to you, or whether cover you already hold includes them, the enquiry form brings you a no-cost phone call from a broker who holds FCA authorisation, and nothing obliges you to go ahead. Cover sold as combined or additional critical illness cover pays out differently again, as combined and additional critical illness cover explains.

Frequently asked questions

Is critical illness the same as terminal illness?

No. A critical illness is a condition on an insurer's list that meets its definition, such as a cancer, heart attack or stroke of a specified kind. A terminal illness is one that a consultant expects to lead to death within a stated time, 12 months in the Legal & General, Aviva and Royal London wording quoted above. An illness can sometimes be both, which is why the policy wording matters.

Does critical illness cover include terminal illness?

Sometimes. Aviva's Critical Illness Plan counts terminal illness among its critical illnesses, while Royal London's six serious illnesses leave it out and both Royal London and Legal & General place terminal illness cover in the life policy instead. The list in your own policy conditions shows which applies to you.

Is serious illness cover the same as critical illness cover?

The names vary by insurer, and the list of conditions and its definitions matter more than the label. Royal London, for example, calls its optional cover Serious Illness Benefit and covers six defined illnesses, while Legal & General and Aviva use "critical illness". A broker can compare the lists on real quotes for free.

Do I pay extra for terminal illness cover?

Legal & General shows terminal illness cover as included with its life insurance, Aviva's Life Insurance Plan provides it alongside the life cover, and Royal London's terms describe it as part of the life cover. Royal London says Serious Illness Benefit, by contrast, is an optional cover you pay extra for. What your own policy charges is shown in your quote and schedule.

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