Credit Corp's US debt buying business drove strong growth in the company's revenue and earnings during the December 2019 half.Credit Corp reported net profit of A$38.6 million for the half - an increase of 15 per cent over the previous corresponding period. Profit from US debt buying was up 27 per cent to $3.3 million.Revenue of $190.9 million was up 20 per cent on the previous corresponding period. US debt buying revenue was up 61 per cent to $28 million.All the company's business divisions made a contribution. Earnings from the Australian and New Zealand debt buying division rose 12 per cent to $25.7 million and earnings from the lending division rose 20 per cent to $9.6 million.The company said the performance of its local debt buying business was assisted by the exclusion of some competitors by debt issuers. It says industry consolidation is underway, driven by heightened compliance sensitivity.It says it is in a strong position to take advantage of consolidation, with $170 million of debt capacity.It expects to make debt purchases worth $310 million to $320 million this financial year - up from $228 million in 2018/19.The Australian and New Zealand debt buying portfolio has a face value of $7.8 billion in 1.3 million accounts. The number of accounts under payment arrangements rose from 157,000 in June to 200,000 in December, with a face value of $1.4 billion.The company said compliance was a highlight: it had no regulatory action of enforceable actions during the half; it had a low complaint rate with its US regulator; and its EDR complaint rate in Australia was lower than peers.On the consumer lending side, where it operates as Wallet Wizard, the loan book grew 13 per cent to $230 million. It forecasts that net lending will grow from $64.1 million in 2018/19 to as much as $83 million in the current year.