Critical illness cover and income protection are often mentioned in the same breath. They're not interchangeable: each serves a different purpose, and understanding the difference is the key to choosing the right one, or deciding you want both.

How they pay out

Critical illness cover pays a one-off, tax-free lump sum if you're diagnosed with a specified condition (such as cancer, stroke or heart attack) and survive a set period (usually around 10 to 14 days). You receive the money regardless of whether you can return to work, and the policy then ends.

Income protection pays a regular monthly benefit (typically up to around 60% of your earnings) for as long as you're unable to work due to illness or injury. It doesn't pay a lump sum, and it doesn't pay out if you can still work. Instead, it replaces lost income over time and can keep paying for years.

What they cover

Critical illness policies cover a defined list of conditions: usually around 40 to 50, sometimes over 100. If your condition isn't on the list or doesn't meet the precise definition, no benefit is payable. Income protection is broader: it covers almost any condition that prevents you from working, including the mental health and musculoskeletal problems that account for a large share of long-term absences. In 2024, musculoskeletal issues such as back and neck pain were the single biggest cause of individual income protection claims.

How often they pay out

Both products pay the large majority of claims. Across all protection policies, around 97% of new claims were paid in 2024. Income protection sits at the higher end of that range, while critical illness is a little lower (roughly 90%) because its claims hinge on meeting specific condition definitions. Where critical illness claims aren't paid, it's most often because the condition didn't meet the definition or because of non-disclosure when the policy was taken out.

What they cost

Cost depends on your age, health, occupation and the cover you choose. As a rough rule, comprehensive long-term income protection can cost more than a similar amount of critical illness cover, because it may pay out for many years rather than once. That doesn't make one better value than the other: they're solving different problems, and the cheaper option isn't automatically the right one.

A quick way to think about it

Critical illness answers the question "what if a serious illness hits me with sudden, one-off costs?" Income protection answers "what if I can't work, and my regular income stops, for months or years?" Critical illness is a lump sum tied to a defined list of conditions; income protection is an ongoing income tied to your ability to do your job. Seen that way, they're less rivals than two halves of a fuller safety net.

The case for having both

They complement each other well. A heart attack might trigger a critical illness lump sum to clear debt or adapt your home, while income protection provides ongoing monthly income if you can't return to work for an extended period. Together they address both the one-off financial shock and the slow drain of lost earnings.

If you can only choose one

There's no universal answer, but a common starting point is to protect the risk that would do the most damage. For many households, that's the loss of a regular income over a long period: the gap income protection is built to fill, and one that covers a far wider range of conditions. Critical illness then adds a valuable lump sum on top if the budget allows. Your own priorities, debts and any cover you already have through work should drive the decision.

Don't forget life insurance

Neither product pays out simply because you die: that's the job of life insurance. For households with a mortgage or dependants, life cover is often the foundation, with critical illness and income protection built around it. Looking at all three together usually gives a clearer picture than considering any one in isolation.

The bottom line

Critical illness cover and income protection answer two different questions. The right mix depends on your circumstances, budget and any existing cover, and an adviser can help you weigh them up and avoid paying for overlap you don't need.