State statutes describe what constitutes dormancy.
It is not usually considered by past due rental payments, but more by loosing contact with the customer. Some states go as far as looking at the entire relationship for dormancy and eschetement - if you are active in one (of many accounts) all the relationships are considered active [even if you haven't used your savings account for a few years].
You might be best to check with your state law for definitions.
Integrity. With it, nothing else matters. Without it, nothing else matters.