Worth it for some households, honestly not for others — and the deciding variable is what a serious diagnosis would break in your finances. The strongest case: a mortgage and dependants resting on your income, limited savings, and sick pay that runs out in weeks — there, a tax-free lump sum (the 2025 average was £67,000) at the worst moment of your life is transformative, and insurers genuinely pay: around 90% of claims industry-wide, over £1.25 billion a year for five consecutive years. The weakest case: no dependants, a solid emergency fund, generous employer sick pay, or a budget where CI’s premiums (multiples of life insurance for the same sum) would crowd out better protection. The critique consumer champions make is fair and worth hearing: income protection often covers the likelier risks better — it pays monthly for any medical inability to work, including the back problems and mental health conditions that dominate real absence but appear on no critical illness list. The honest sequence most advisers land on: life cover first if anyone depends on you, then income protection or critical illness sized to budget — and for many, a blend of modest amounts of each beats a heroic amount of one.

Around 90% — the 2025 industry figure across ABI and group data was 90.2% of critical illness claims paid, with most major insurers above 90% and the best around 93%. That’s high enough to demolish the ‘they never pay’ folklore, and the roughly one-in-ten that fail teach exactly two lessons. Lesson one: non-disclosure — the health history unmentioned at application, discovered when the insurer checks GP records at claim time; the fix costs nothing and is simply answering every question completely. Lesson two: definitions — the diagnosis that didn’t meet the policy’s wording: the TIA that isn’t a stroke, the early-stage cancer below the severity bar, the heart event without the required markers; the fix is choosing policies for definition quality rather than brochure condition-counts, and understanding that ‘additional payment’ conditions exist precisely to pay partial sums for the earlier-stage diagnoses the main definitions exclude. Read together, the claims data says something genuinely reassuring: a properly disclosed application against a well-worded policy is very likely to pay — the product works; the failure modes are avoidable and live mostly at the application stage.

The most useful comparison in protection, so here it is with real numbers. Income protection pays a monthly amount (typically 50–65% of salary) for as long as you medically can’t work — potentially years, potentially to retirement — and it covers any qualifying inability to work, which matters enormously because the conditions that actually keep Britons off work long-term are musculoskeletal problems (about a third of IP claims) and mental health (roughly a fifth): conditions critical illness cover essentially never pays for. The average IP claim runs about £10,700 a year, and long claims accumulate past any lump sum. Critical illness pays once — the 2025 average was £67,000 — on diagnosis of a listed condition, survival period met, and its unique power is immediacy and freedom: a lump sum weeks after diagnosis, spent on anything, no ongoing claim assessments. The honest matching: IP protects your income against the likely (the bad back, the breakdown, the long recovery); CI protects your balance sheet against the catastrophic (the cancer diagnosis with a mortgage attached). Self-employed people usually need IP more than they realise; mortgage-holders feel CI’s logic hardest. Budget for one? IP usually covers more real-world risk per pound. Budget for both, modestly sized? That’s the combination most protection advisers quietly build for their own families.

This is the scenario the product was practically designed for, so the case is at its strongest — with the honest caveats still attached. The logic: your mortgage is the largest bill that doesn’t pause for chemotherapy, and a lump sum that clears or substantially reduces it converts a financial catastrophe into a medical challenge — which is why combined life-and-critical-illness policies aligned to the mortgage (decreasing with a repayment mortgage, level with interest-only) are the market’s most-bought structure, and why cancer — 65% of all CI claims — so often arrives mid-mortgage, in claimants’ working years. The caveats that keep it honest: no lender requires critical illness cover (life cover is often expected; CI is a choice — decline any suggestion otherwise), the accelerated structure of most combined policies pays once (a CI claim ends the life cover too — worth understanding before, not after), and full mortgage-sized CI cover is expensive, which makes partial cover — enough to buy two or three mortgage-free years rather than total clearance — the pragmatic middle path many households actually sustain. Priced against your own mortgage and age, the answer stops being philosophical: it’s a number, and comparing it takes minutes.