Almost a quarter of all complaints to the Credit & Investments Ombudsman during the 2014/15 financial year related to credit reporting. Complaints about credit reports now rank alongside complaints about financial hardship as the biggest issue the CIO deals with.CIO chief executive Raj Venga said: "It is a much bigger part of the work we do than it was a few years ago."There are a couple of reasons for this: with the advent of comprehensive credit reporting consumers are being educated to understand their credit reports and check them for errors or inappropriate listings; and credit repair companies promote their ability to have negative listings removed.Venga said he did not see a problem with the credit reporting system. "Our experience is that the listings are usually accurate. It is more often a question of whether the matter should have been listed in the first place," he said."For example, a default may be listed while the consumer is negotiating for hardship assistance with the credit provider. Or there may be a default listing on a loan that should never have been made."According to the CIO's 2014/15 annual report, the organisation received 4848 complaints during the year to June - a 7.4 per cent increase over the previous year.Most of that increase was due to an increase on the organisation's membership, which rose 11.8 per cent to 20,475. On a like-for-like basis complaints were up about one per cent, which is a similar rate of growth to that reported by the Financial Ombudsman Service.Sixty-four per cent of complaints were resolved within three months and there were only two cases older than 12 months. The number of complaints that were closed rose eight per cent, compared with 2013/14.The proportion of financial hardship cases has fallen from a high of 34 per cent of all cases to 24 per cent in 2014/15. FOS also reported a decline in complaints related to hardship.Disputes over consumer finance (credit cards, motor vehicle finance, personal loans, consumer leases and retail finance) accounted for 68.6 per cent of all complaints, home finance accounted for 16.3 per cent of complaints and property investment finance accounted for 3.4 per cent.The groups most often subject to complaints were debt collectors and purchasers. CIO pointed out that complaints about these organisations might relate to the conduct of either the debt collector (or purchaser) or the original credit provider.Credit Corp attracted 349 complaints (the highest number), Baycorp 206, ACM Group 149 and Pioneer Credit 83.Among consumer finance companies FlexiGroup attracted 140 complaints and Thorn Group 37, and among motor vehicle finance providers Nissan Financial Services attracted 56 complaints and Volkswagen Financial Services 40.