There are a few ways a Promissory Note becomes invalid:
Amendments: Both parties must sign off on any changes to the original agreement.
Losing the original version: Even if amendments are made to the agreement, the lender should keep a copy of the original version to help prove the new agreement’s legitimacy.
Missing key details: A Promissory Note must include the payment amount and schedules, interest rates, and both parties' signatures.
Unclear terms: A court needs to be able to interpret the agreement to enforce it. LawDepot’s template can help you clearly outline your agreement’s terms.