Tortured advocates of comprehensive credit reporting have been handed a slice of hope after National Australia Bank announced it would begin sharing customers' credit data with other institutions in February next year.NAB is the first of the major banks to voluntarily commit to the expanded credit reporting system that is aiming to widen credit history data shared between credit providers.The bank's decision follows a warning earlier this year from Treasurer Scott Morrison that the federal government would prepare legislation to mandate banks' participation in the new reporting regime.Morrison said a mandatory system would be introduced if lenders were not reporting 40 per cent of credit data before the end of the year.Industry experts said last month that lenders were only divulging less than five per cent of the information they were required to disclose under CCR.It is a remarkably dismal outcome for the system, which was launched with great fanfare in March 2015 by the Australian Retail Credit Association.Banks have been sharing negative information about borrowers for decades, but CCR requires them to release positive credit details including types of accounts opened by customers, limits on credit cards and monthly payments records.The system will enable prospective lenders to build comparatively rich profiles of loan applicants and then price credit for risk.The big banks have been delaying their participation in CCR framework amid concerns that lending rivals would begin cherry-picking their low-risk borrowers with low-ball credit offers.NAB's chief operating officer, Antony Cahill, said CCR would provide a more complete picture of a customer's situation and "mean that lenders like NAB are better able to match the provision of credit to a customer's individual needs"."Most Australians have a credit report, and with Comprehensive Credit reporting, these reports will represent a more balanced reflection of their credit history," he said."CCR will help ensure customers get the right product and credit that's suitable for their needs, and it will drive more competition in the industry."Banks are sensitive to the reality that CCR will strategically position regulators such as the Australian Securities and Investments Commission to enforce compliance with responsible lending laws.NAB will phase in CCR throughout 2018, beginning with personal loans, credit cards and overdrafts.