What are the usury limits under Washington state law

late fees for services: I do tax returns and bookkeeping for clients most people pay no problem but what is the max I can charge for late fees if I get a client that decides not to pay. I am asking because a partnership after I did a lot of work decided not to pay after they broke up the partnership and the partner that kept the partnership decided he did not have to pay me because he did not hire me. All other bills were paid but a $30. one that is not a big deal but it is the point. Oh and they are in MN and I am in WA. - Is this your question? Add additional information