We charge interest from the date funds are disbursed, usually the 4th day. I believe Reg Z allows either method, dependent on the individual states. PA is silent on this, at least I've never been able to find it. So, I don't have a reference in the PA code for you, but seem to recall some concerns with this years ago in PA. From our viewpoint, charging interest from when funds are disbursed was always easier to explain to a customer. If you are paying off other debt, such as credit cards, the customer could challenge that you are trying to "double dip" on interest, since they are usually charged interest to the payoff date, which is usually your disbursement date. You of course will get 3 additional days of interest, but I guess it boils down to "Is it worth it?". You may want to search out the PA Dept. of banking website, under on-line resources. I would probably also consult an attorney, who could fill you in on any class action or other cases that may have involved this issue.