Q2) "Can I charge them interest and if so how do I calculate the appropriate amount?"
A2) Earlier in your message you said, "said business agreeing to pay me the principal and interest on that loan by a certain date.". From this, I assume you are already getting interest. Why is this now an issue?
My point here is that they agreed to return my principal and pay me interest for a given length of time. By exceeding that without my consent they are, in effect, getting "free" use of my money between the time the loan should have been repaid and the time when it is actually repaid. I'm wondering if I can charge them interest for the delinquent period and if so, how is an interest figure usually calculate??
How does your agreement read?? Most notes will say something to the effect... "plus 10% annual interest until paid".
Q3) "Can I compell them to pay the balance owed me in full and if so how do I go about this."
A3) You can certainly file a lawsuit to try to get payment in full, but you stand the risk of additional cost and time in bringing them to court. There is also a risk that they might mount a defense against your claims and have your entire agreement voided (if you are charging excessive interest for example).
This last point you make about excessive interest raises a question for me. If the court deems interest "excessive", does it matter who initially suggested that interest rate. For example, if someone approaches me and offers to pay me 10% on my money for a 1 week loan (hypothetical figures here) and the court finds that rate to be excessive, does it matter that the interest rate was not set by myself but rather was suggest by the borrower of the money?
This one is pretty simple... it doesn't matter who suggests the interest rate, if it is excessive, the courts could void the entire agreement.
Also, how does the court define "excessive" relative to loans?
Your state mandates a maximum allowed interest. If your agreement exceeds that amount, it is 'usury'.
