Not so related grammar question.

I want to convey that I’m not in any default fees. Would I answer Yes or No to the statement below?

I am not in default of any fee

also, I can’t follow up my yes or no answer with “I’m not in any default fees”.

I would take “yes” to mean “correct.”

Agree with @bodangles. If the statement was “I am in default …” then I assume you would have no problem with what yes and no meant. Well, just flip those answers. I.e., if the answer to “I am in default” is NO, then the answer to “I am not in default” is YES.