The company's collection success rate has slipped by a few percentage points. Gert van Laar, chief executive, said debtors were finding it harder to pay because of the accumulation of different sorts of debt.
This problem would prevent Intrum from achieving the 20 per cent increase in earnings that it achieved last year, though Mr van Laar said the company still expected a good rate of growth this year and next.
Pre-tax profits for the first six months of the year rose 33 per cent to pounds 6.1m. Turnover was up by 12 per cent to pounds 40.8m, aided by Eureco, the French debt-collector bought earlier this year.
Intrum has pounds 1.2bn of debts to collect, a 19 per cent increase since the start of the year. The UK workload went up by 17 per cent to pounds 440m. Intrum's clients pay a commission of 15-50 per cent of the value of the debt, depending on its type and age.
The interim dividend was up by 25 per cent to 1p a share.