In legal|lang=en terms the difference between debtor and debtee

is that debtor is (legal) one who owes another anything, or is under obligation, arising from express agreement, implication of law, or principles of natural justice, to pay money or to fulfill some other obligation; in bankruptcy or similar proceedings, the person who is the subject of the proceeding while debtee is (legal) one who is owed a debt; a creditor.

As nouns the difference between debtor and debtee

is that debtor is (economics) a person or firm that owes money; one in debt; one who owes a debt while debtee is (legal) one who is owed a debt; a creditor.