The royal commission into misconduct in banking has reached the sixth and final topic of the consumer credit topics to be addressed in the course of these hearings - credit card lending.  To set the scene, Albert Dinelli, counsel assisting, told the hearing that as at January of this year, there were 16.7 million credit card accounts in Australia.  "In the same month, that is, in January of this year, the total value of outstanding balances on credit cards in Australia was 51.6 billion, of which 32.6 billion was incurring interest," he said.The hearing later heard testimony from David Harris, "a CBA customer who had a gambling problem of which CBA was aware, at least when credit limit increases were offered, and perhaps ought to have been aware earlier.  Nevertheless, Mr Harris was offered a credit limit increase only days after telling the Commonwealth Bank of his problem," Dinelli explained.Harris was well employed in the building trade, but developed a gambling habit. He ended up "maxing out" two credit cards and when he tried to call the CBA for help - essentially to work out a way of paying down the cards, was instead offered a third card which funded further gambling.Calls to the bank explaining his problem resulted in a consolidation of debt, which by then had blown out to $27,500 …. and another CLI (credit limit increase) offer which he resisted then accepted, hoping to gamble his way back to solvency, but ended with a $35000 credit card debt with a yearly income of 70,000.Clive van Horen, executive general manager of retail banking at CBA, was recalled to the witness box to explain the circumstances of Harris's woes.He agreed that this goes to the responsible lending question, and the next step in the responsible lending processes, is to test for serviceability and suitability."We've acknowledged we should not have provided that final credit limit offer," van Horen said."And the basis for saying that is, having had the conversation with one of our staff members in a contact centre and declaring that Mr Harris had a gambling problem, to use the simple description of it, without in any way trying to minimise the challenge that presented, that information was not in any way passed through to credit decisioning systems.  "And, you know, that's a failing and we acknowledge that and we've got to find ways to address that.  So, to that extent, having declared it to somebody working in the Commonwealth Bank, we did not use that information for the subsequent credit offer [of a further $8000]."Van Horen also told the royal commission that as a result of this case, the bank has changed its credit decisioning rules to avoid offering "significant" credit limit increase is similar circumstances as the credit team can now look at gambling spend not just on the current credit card, but on any other accounts as customers are shifting funds between accounts.Limits now are applied, based on percent of income or a total amount."But gambling