Zurich's half year results showed 91% of critical illness claims were paid out.
The payments amounted to £32.7m and the number of claims paid out for its UK life policy customers was 411; with one policy paying out £1.05m.
Non-disclosure was cited as the reason for 1.5% of declined claims and the remaining 7.5% were turned away because condition definition was not met.
Peter Hamilton, head of protection proposition at Zurich, said: "In the small proportion of cases where claims can't be paid, it's largely because the condition suffered does not meet the terms of the policy. As a nation, we remain hugely under insured; cover such as this is an essential element of sound financial planning.
"It is also encouraging to see claims declined due to non-disclosure rates remaining low. Investment by the industry into initiatives to help improve understanding of the issues seem to be paying off."
Cancer was the most common reason for payments at 60%.
Heart attack accounted for 13% and stroke for 7%, while benign brain tumour and multiple sclerosis each accounted for a further 5% of payments.
Zurich publishes both annual and six-monthly critical illness claims statistics.