Our office is looking into what a reasonably accepted rate to charge for past due accounts would be. We, of course, would have to put this into the initial contracts as well but since we are a sole practitioner firm (Probate/Family Law) we need to know what is considered reasonable. 12% ? 10% ?
I am not aware of any industry standard. Although you label the amount as a later fee, it appears to be an interest charge and you do not want to violate the usuary laws. 12% would seem reasonable.