Credit insurance claims have surged in the first three months of the year, reflecting a big increase in bad debt levels throughout the business community.Broker National Credit Insurance reported yesterday that the number of claims lodged in March was up 67 per cent on the same time last year. NCI marketing manager Terry Duffy said claims in January and February were also much higher than last year.Duffy said the industries that were showing high claim numbers were construction, electrical, paper, printing, automotive and advertising.Duffy estimated that about five per cent of Australian businesses take out insurance to cover their receivables. Financial institutions use it to for security over their receivables' finance books."What these figures indicate is that business conditions are very tough. Margins have been under pressure for some time and now sales are down. "The banks must have a lot of non-performing loans on their books."