Is it legal if when you became an authorized user on your mom's credit card account they told her they would only report the account on your credit report if it was or became negative?

The credit card company should be reporting each month whether your mom pays her account on time or is late. The "only if it is negative" refers to things such as hospital/phone bills, etc. But with revolving credit they absolutely should be reporting. I am not sure who exactly you should contact; perhaps the Better Business Bureau first. If they can't help they should have information on who can. If you are an authorized user on your mothers account, your credit score should not be effected if the account becomes delinquent. If this account shows up on your credit report you can dispute it with the major reporting agencies: Experian, Equifax and Transunion. Both answers above are misleading. There is no federal or state law that compels or requires credit reporting. It is not only a voluntary activity, but one that Data Furnishers have to pay for. Therefore, it is their decision (often business policy) whether or not to report and how often. If your particular AU account is not reported, there is nothing illegal about it and no one to complain to. But, a good idea would be to check reporting policies PRIOR to being added as an AU. If your goal was to add credit data to your consumer file, a non-reporting creditor was not a good choice.