A promissory note is a written, legally binding document in which one party (the maker) promises to pay a specific sum of money to another party (the payee), either on a set date or whenever the payee demands it. Under the Uniform Commercial Code, it qualifies as a negotiable instrument when it contains an unconditional promise to pay a fixed amount, is payable to a named person or bearer, and is payable on demand or at a definite time.1Legal Information Institute. UCC 3-104 – Negotiable Instrument That negotiable status matters because it means the note can be sold or transferred to third parties, and those new holders can enforce it independently of the original lender. Promissory notes show up in family loans, mortgages, student loans, car financing, and business lending, and the rules governing them carry real consequences for both sides.
How It Differs From an IOU and a Loan Agreement
People often lump these three documents together, but each carries different weight in court.
An IOU is the simplest. It acknowledges that a debt exists, usually with a line like “I owe you $5,000,” and nothing more. It typically does not include repayment terms, interest, or consequences for nonpayment, which makes it difficult to enforce if the borrower stops cooperating.
A promissory note sits in the middle. It is a one-directional promise from the borrower to the lender, spelling out the amount owed, the interest rate, the repayment schedule, and what happens on default. Because it qualifies as a negotiable instrument under the UCC, it enjoys stronger legal protection than an IOU and can be transferred to new holders.
A loan agreement is the most comprehensive of the three. It is a mutual contract in which both parties make commitments: the lender agrees to provide funds under certain conditions, and the borrower agrees to repay under detailed terms. Loan agreements typically address collateral, representations and warranties, financial covenants, and events that would let either party modify the arrangement. When the loan is large, when multiple lenders or co-signers are involved, or when the deal has complex conditions, a loan agreement offers protections that a standalone promissory note does not.
What Has to Be in the Note
A promissory note doesn’t need to be long, but it does need to cover specific ground. Missing even one element can make the note unenforceable or create ambiguity a borrower could exploit later.
- The full legal names and contact information of the maker (borrower) and payee (lender).
- The exact principal amount being loaned.
- The interest rate: whether it’s fixed or variable, whether interest is simple or compound, and how often it accrues.
- The repayment schedule: dates, frequency, and amounts of each payment, and whether the loan is paid in installments or as a lump sum.
- The maturity date, meaning the final deadline by which the entire remaining balance must be paid.
- Late payment penalties: any fees or higher interest rates that kick in when a payment is overdue.
- Prepayment terms: whether the borrower can pay off the loan early and whether a prepayment penalty applies.
- Default provisions: what counts as a default and what remedies the lender can pursue, including any acceleration clause.
- Governing law: which state’s law controls disputes over the note.
One item people overlook is consideration, the legal term for what the borrower actually receives in exchange for the promise to repay. In most notes, consideration is the loan proceeds themselves. But if a note is signed without any exchange of value, the borrower can raise lack of consideration as a defense to avoid payment. UCC Section 3-303 preserves that defense even for negotiable instruments, so a signed note is not automatically bulletproof.
Co-Signers and Guarantors
When a borrower’s credit or income isn’t strong enough on its own, the lender may require a co-signer or guarantor. The roles sound similar but differ in timing. A co-signer shares equal responsibility for every payment from day one, so if the borrower misses a single payment, the lender can immediately pursue the co-signer for that amount. A guarantor becomes responsible only after the borrower has fully defaulted, meaning the lender must first exhaust remedies against the borrower before turning to the guarantor. The note should state clearly which role the third party is taking on, because the distinction directly affects when and how the lender can collect.
The Main Types of Promissory Notes
Notes come in several varieties, each suited to different lending situations. The two most fundamental distinctions are whether the note is backed by collateral and how repayment is structured.
Secured vs. Unsecured
A secured note is backed by a specific asset the lender can seize if the borrower defaults. The collateral might be real estate, a vehicle, equipment, or a financial account. Because the lender has a fallback, secured notes typically carry lower interest rates and are easier to obtain. If the borrower stops paying, the lender can repossess or foreclose on the pledged asset.
An unsecured note relies entirely on the borrower’s promise and creditworthiness. Nothing is pledged. If the borrower defaults, the lender’s only path is filing a lawsuit, obtaining a judgment, and then using collection tools like wage garnishment or bank levies. That added risk usually translates to a higher interest rate.
Installment vs. Demand
An installment note requires the borrower to make regular payments (monthly, quarterly, or on another schedule) until the debt is fully paid. Each payment usually includes both principal and interest. This is the standard structure for car loans, mortgages, and personal loans because both sides know exactly what to expect.
A demand note has no fixed repayment schedule or maturity date. The full balance becomes due whenever the lender formally requests payment. If the note is silent on when payment is due, the UCC treats it as payable on demand by default. Demand notes are common in lines of credit and some business lending, where the lender wants flexibility. The borrower needs to understand that the lender can call the entire balance at any time.
Real Estate Notes
In a home purchase, the promissory note and the mortgage (or deed of trust, depending on the state) are separate documents that work together. The note is the actual debt obligation: it establishes how much the borrower owes, the interest rate, the monthly payment, and the consequences of default. The mortgage or deed of trust is the security instrument that gives the lender the right to foreclose if the borrower stops paying. The note creates the debt; the mortgage protects the lender’s ability to collect it. If the borrower defaults, the lender can sue on the note for a money judgment regardless of what happens with the property.
Master Promissory Notes
A master promissory note is a single document that covers multiple loan disbursements over time rather than one lump-sum loan. Federal Direct Loans are the most common example: a student signs one master note at the beginning, and that note governs every disbursement for up to ten years. No new note is signed each semester. The advantage is administrative simplicity, but the signer is also agreeing in advance to the terms of loans they haven’t yet received.
Signing, Notarization, and E-Signatures
The maker must sign and date the promissory note for it to be enforceable. The payee’s signature is not legally required in most situations, because the note is a one-way promise rather than a mutual agreement. Both parties should keep copies, and the original should go to the payee. Physical possession of the original note matters for enforcement; if the lender loses it, pursuing a claim becomes significantly more complicated.
Under the federal Electronic Signatures in Global and National Commerce Act, an electronic signature carries the same legal weight as a handwritten one for transactions in interstate commerce.2Office of the Law Revision Counsel. 15 USC 7001 – General Rule of Validity A contract cannot be denied enforceability solely because it’s in electronic form. For the electronic signature to hold up, the signer must show intent to sign, both parties should consent to conducting the transaction electronically, and the signed document must be retained in a form that can be reproduced later.
Notarization is not required for a promissory note to be valid, but it adds protection. A notary verifies the signers’ identities and witnesses the signing, which makes it harder for either party to later claim they never signed or that a signature was forged. For secured notes tied to real estate, the security instrument itself usually must be notarized and recorded with the county, even though the note doesn’t.
Interest, Usury, and the Family-Loan Tax Trap
Interest is the lender’s compensation and the borrower’s cost. Most promissory notes charge it, and the rules around what can be charged and how the IRS treats it are where people routinely make mistakes.
Usury Limits
Every state sets a maximum interest rate for private loans, known as the usury limit. There is no single federal cap on interest rates for all consumer lending. State limits vary widely, and the consequences of exceeding them range from forfeiture of all interest to voiding the loan entirely. Some states impose criminal penalties. Before setting an interest rate on a private note, check the usury limit in the state whose law governs the note. This matters most for loans between individuals, where no institutional compliance department catches the mistake.
Below-Market Loans to Family or Friends
Lending money to a family member or friend at zero interest, or at an artificially low rate, triggers IRS scrutiny. Under 26 U.S.C. ยง 7872, if a loan charges interest below the Applicable Federal Rate published monthly by the IRS, the agency treats the “forgone interest” (the difference between what was charged and the AFR) as though it were actually paid.3Office of the Law Revision Counsel. 26 USC 7872 – Treatment of Loans With Below-Market Interest Rates For a gift loan between family members, the IRS treats the forgone interest as a gift from lender to borrower and, at the same time, as interest income paid back to the lender. The lender owes income tax on interest they never actually received.
There is a de minimis exception: if the total outstanding loans between two individuals stay at or below $10,000, Section 7872 does not apply, unless the borrower uses the money to buy income-producing assets like stocks.3Office of the Law Revision Counsel. 26 USC 7872 – Treatment of Loans With Below-Market Interest Rates For loans between $10,000 and $100,000, the imputed interest is capped at the borrower’s net investment income for the year. Above $100,000, no cap applies. As of April 2026, the short-term AFR is 3.59%, the mid-term rate is 3.82%, and the long-term rate is 4.62%, compounded annually.4Internal Revenue Service. Rev. Rul. 2026-7 – Applicable Federal Rates for April 2026 Which rate applies depends on the loan term: short-term for loans up to three years, mid-term for three to nine years, long-term for anything beyond nine years.
Reporting the Interest You Receive
Any person who pays $10 or more in interest during a calendar year must file Form 1099-INT with the IRS and provide a copy to the recipient.5Internal Revenue Service. Instructions for Forms 1099-INT and 1099-OID Private lenders often overlook this because they think of the 1099-INT as a bank form. It isn’t. If you lend a friend $50,000 at 5% interest and receive $2,500 in interest during the year, you’re required to file a 1099-INT. And even if the interest received is under $10 and no 1099 is required, the lender still has to report the income on their return.
Transferring the Note and Why Borrowers Should Care
Because a properly drafted promissory note is a negotiable instrument, it can be sold or transferred to someone other than the original lender. This happens constantly in the mortgage industry, where banks bundle notes and sell them to investors, but it can happen with any negotiable note.
Transfer happens through endorsement, similar to endorsing a check. A special endorsement names the specific person or entity to whom the note is being transferred, and only that person can then negotiate it further. A blank endorsement is just the payee’s signature without naming a new recipient, which makes the note payable to whoever physically holds it. A blank-endorsed note is essentially cash.
The biggest consequence for the borrower is the holder in due course doctrine. Under UCC Section 3-302, a person who acquires a note for value, in good faith, and without knowledge of any problems with it becomes a “holder in due course.”6Legal Information Institute. UCC 3-302 – Holder in Due Course That status strips away most defenses the borrower might have had against the original lender. If you signed the note because the original lender made oral promises they didn’t keep, you can raise that defense against the original lender but generally not against a holder in due course who bought the note without knowing about those promises. Many borrowers get caught off guard here.
What Happens if the Borrower Defaults
Default happens when the borrower fails to meet the obligations spelled out in the note. The most common trigger is a missed payment, but default can also result from violating other terms, such as failing to maintain insurance on collateral or letting a lien attach to pledged property.
Acceleration Clauses
Most well-drafted promissory notes include an acceleration clause, which lets the lender declare the entire remaining balance due immediately after a default. Without it, the lender can only sue for the missed payments, not the full amount. Acceleration clauses usually do not trigger automatically. The lender has to invoke the clause, and if the borrower cures the default before the lender acts, the lender may lose the right to accelerate.7Legal Information Institute. Wex – Acceleration Clause In the mortgage context, some jurisdictions let borrowers undo an acceleration by catching up on missed payments and covering the lender’s costs before foreclosure is finalized.
The Collection Path
After declaring default, the lender typically sends a formal demand letter specifying the amount owed and a deadline. If the borrower doesn’t pay, the lender files a lawsuit, and the promissory note itself serves as the primary evidence of the debt. Because the note is a written contract with clear terms, these cases tend to be more straightforward than disputes over oral agreements.
If the court rules for the lender, a judgment establishes the debt as a legal obligation. That opens up collection tools: wage garnishment, bank account levies, and liens on the borrower’s property. For secured notes, the lender can also pursue the collateral directly, repossessing and selling it to satisfy the debt. Any shortfall remaining after the collateral is sold (called a deficiency) can still be pursued as an unsecured claim, depending on the state.
How Long the Lender Has to Sue
Lenders don’t have unlimited time to enforce a note. Under UCC Section 3-118, a lawsuit to enforce a note payable at a definite time must be filed within six years after the due date, or within six years after an accelerated due date if the lender invoked an acceleration clause. For demand notes, the six-year clock starts when the lender actually makes a demand. If the lender never makes a demand and no principal or interest has been paid for ten continuous years, the right to enforce the note expires entirely.8Legal Information Institute. UCC 3-118 – Statute of Limitations Some states have adopted different time periods, so the UCC’s six-year default is a starting point rather than a universal rule.