Promissory Note in Business Acquisitions: What It Is and What to Include

By Charlie Brennan • Published June 22, 2026 • Updated June 22, 2026 • Educational content only — not financial, legal, or tax advice.

A promissory note is the legal document that records a debt obligation. In a business acquisition, it's the instrument the buyer signs to formalize seller financing — a written promise to pay the seller a specified amount, on a specified schedule, at a specified interest rate. Without a properly drafted promissory note, there's no enforceable debt instrument, and the seller has no legal basis for collection.

What a Promissory Note Must Include

Secured vs. Unsecured Notes

A promissory note can be unsecured (based solely on the buyer's promise to pay) or secured by a lien on business assets. Sellers should almost always insist on a secured note backed by a UCC financing statement filed with the state — this gives the seller a perfected security interest in business assets, allowing them to seize assets in the event of default. An unsecured note requires a lawsuit and judgment before any collection can proceed.

If there's also an SBA loan, the bank's lien is senior — the seller's security interest is subordinate. But a subordinate lien is still meaningfully better than no lien.

Standby Provisions

When SBA financing is involved, the SBA requires the seller note to be on full standby for 24 months — no principal or interest payments from the business to the seller during that period. This standby requirement is memorialized in the promissory note itself and in a separate standby agreement signed at closing.

Promissory Note vs. Seller Note

These terms are used interchangeably. "Seller note" typically refers to the concept of seller-financed debt in a deal; "promissory note" refers to the specific legal document recording that debt. The seller note is evidenced by a promissory note. Both terms appear in deal negotiations — they mean the same thing in context.

Related Terms

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Charlie Brennan

Studied M&A deal structures by analyzing 50+ business acquisition opportunities, with a focus on valuation, financing terms, seller motivations, and operational risk. Built practical acquisition tools for business buyers.