Lenders that do not upgrade their credit reporting systems and participate in the new comprehensive reporting regime may run the risk of not meeting their responsible lending obligations, an industry expert has warned.Comprehensive credit reporting rules took effect on March 12 and many lenders are weighing up the cost of upgrading from negative to positive reporting.However, speakers on a panel at yesterday's Australian Securities and Investments Commission annual forum questioned whether a lender that did not access comprehensive credit reports could fulfil its responsible lending obligations.Under the responsible lending rules of the National Consumer Credit Protection Act, a financial services provider must do three things to be satisfied that a credit contract is "not unsuitable" for a borrower: it must make reasonable inquiries about the consumer's requirements and objectives; it must make reasonable inquiries about the consumer's financial situation; and it must take reasonable steps to verify the consumer's financial situation.The head of consumer compliance at Citigroup, Michael Saadat, said lenders that did not have access to comprehensive credit files could be "vulnerable" if a dispute about the suitability of a loan went to an ombudsman.The new reporting regime allows credit reporting agencies to add the following information to credit files: the date a credit account was opened; the type of credit account opened; the date a credit account was closed; the current limit of each open credit account; and repayment performance history.There is no obligation on lenders to provide comprehensive data to credit reporting agencies -  but under the scheme's reciprocity rule if they do not provide comprehensive data they cannot have access to it.Saadat said: "If a lender is not doing comprehensive reporting and then makes a credit decision that would have been different if the lender did have access to a comprehensive file, then what is the position if a dispute goes to an ombudsman?"If the decision would have been different, taking the extra information about the customer into account, it creates a vulnerability for the lender."NAB Broker Distribution general manager, Steve Kane, said: "A comprehensive credit report will give a more accurate picture of the applicant's ability to service a loan."But it is early days. We don't know who is going to play and how much information they will issue. It is too early to say how much of an impact comprehensive reporting will have."The lead ombudsman in the banking and finance division of the Financial Ombudsman Service, Philip Field, said: "One of the positives of comprehensive reporting is that it allows you to make a better assessment of the borrower's capacity."But credit history is not the only way to make sure a borrower can manage a loan without difficulty."I have spoken to some lenders who say they have enough information and the cost of getting into the comprehensive reporting system may not be worth it."I don't think it is absolutely necessary for lenders to join the top tier to satisfy their responsible lending obligations."