US property and casualty insurance fraud costs $US32 billion ($35 billion) a year, according to the Insurance Information Institute.

Questionable claims increased 16% from 100,201 in 2011 to 116,171 last year, it says, citing National Insurance Crime Bureau figures.

Common frauds include inflated claims, misrepresented facts on applications, claims for injuries or damage that never happened and staged accidents.

The leading sector for questionable claims last year was personal motor, with 78,024, the figures show. Next up were homeowners’ personal property (17,183) and workers’ compensation (4459).

The top five states for questionable claims were California (21,935), Florida (10,693), Texas (10,368), New York (9059) and Maryland (4296).

Fewer people now believe it is acceptable to increase insurance claims to compensate for deductibles, the report says.

Earlier this year an Insurance Research Council poll found 24% of people considered it acceptable to pad insurance claims, down from 33% in 2002.

Another survey by the Property Casualty Insurers Association of America found 45% of insurers said fraud accounts for 5% to 10% of claims costs; 32% said it was as much as 20%.