The debtor finance market has made a slow start to the year, with invoice discounting and factoring turnover in the March quarter down 10 per cent from the December quarter. The Debtor and Invoice Finance Association reported that the sector's turnover for the March quarter was A$15 billion - down from $16.7 billion in the December quarter.March quarter turnover was 3.1 per cent higher than turnover in the March quarter last year.The bulk of the business ($13.7 billion) was invoice discounting, where the seller of the trade debts retains the accounting and debt collection functions. Factoring (where the finance company takes over the accounting and debt collection) accounted for $1.3 billion of turnover.Client numbers fell from 4503 in December to 4488 in March.