What promissory note means
A promissory note is a promise to pay, written down and signed.
It names the person promising, the person to be paid, the exact amount, and when it falls due. That is nearly all of it. There is no negotiation of terms, no schedule of obligations on both sides, just one party undertaking to pay another.
The law treats it as a negotiable instrument under the Bills of Exchange Act, which gives it a particular strength: it can be transferred, and it stands on its own as evidence of the debt. The person holding it does not have to prove the story behind it before they can sue on it.
That is why it survives in commercial use. A signed note is difficult to argue with. Either you signed a promise to pay two million naira on the thirtieth, or you did not.
How it is used
It suits simple debts where the only question is repayment.
A supplier extending credit to a buyer. A friend lending money and wanting more than trust. A business settling an outstanding balance over three instalments. A shareholder putting money into a company on the understanding it comes back.
A usable note states the date, the amount in words and figures, who is promising and who is to be paid, when payment is due, any interest, where payment is to be made, and the signature of the person promising. Two witnesses cost nothing and make the document much harder to dispute later.
Where the arrangement is more complicated, involving security, covenants, drawdowns, default triggers or a repayment schedule that can change, a loan agreement is the right document instead. Trying to force all of that into a note is how disputes start.
Key features
- An unconditional written promise to pay a fixed sum
- Signed by the person who owes the money
- Payable on demand or at a fixed or determinable future date
- A negotiable instrument under the Bills of Exchange Act, so it can be transferred
- Can carry interest, provided the rate is stated
- Unsecured unless a separate security document is executed alongside it
How this works in Nigeria
Nigerian courts enforce promissory notes readily, and there are procedures for undefended money claims that suit a clean, signed note very well. A defendant who cannot show a genuine defence often cannot delay judgment for long.
Stamping matters more than people expect. Promissory notes attract stamp duty, and an unstamped instrument can face difficulty being admitted in evidence until the duty and any penalty are paid. Stamping at the outset is cheap. Discovering the problem in court is not.
The practical Nigerian reality is that most private lending happens on trust, and the loss lands when a relationship breaks down and nothing was written. A one page note signed and witnessed at the moment the money changes hands is the difference between a debt you can enforce and a disagreement about what was said.
Promissory note vs loan agreement vs IOU
Three documents on a scale from casual to full.
An IOU simply acknowledges that money is owed. It records the debt and usually says nothing about when or how it is to be paid, which makes it weak evidence and an awkward foundation for a claim.
A promissory note goes further. It is an actual promise to pay a stated amount at a stated time, signed by the debtor, and the law treats it as a negotiable instrument. It is short but it is enforceable.
A loan agreement is the full document. It is signed by both parties and deals with drawdown, interest, repayment schedule, security, events of default, remedies and dispute resolution.
Rule of thumb: small amount, simple repayment, use a note. Larger sum, security involved, or repayment over time with conditions attached, use a loan agreement.
Limits and risks
A note is a promise, not a payment, and not security.
It gives you nothing to seize. If the person who signed has no money when the date arrives, you hold a very good piece of evidence and no cash. Where the sum is significant, take security or a personal guarantee from somebody who can actually pay.
It is also inflexible by design. It cannot easily accommodate a repayment schedule that changes, staged drawdowns, or conditions attached to the money.
And limitation periods apply. A note left unenforced for years can become statute barred, and a debt you never chased can quietly stop being recoverable.
Worth knowing
Write the amount in words as well as figures, and have the signature witnessed. Most disputes about notes are about whether the figure was altered afterwards, and words plus a witness closes that argument before it starts.
Questions people ask
What is a promissory note?
It is a written and signed promise by one person to pay a fixed sum of money to another, either on demand or at a stated future date. It is treated as a negotiable instrument under the Bills of Exchange Act.
Is a promissory note legally binding in Nigeria?
Yes. Where it is properly drawn and signed, Nigerian courts enforce it, and a clean signed note is well suited to the procedures available for undefended money claims.
What is the difference between a promissory note and a loan agreement?
A note is a one sided promise to pay a stated sum, short and simple. A loan agreement is signed by both parties and covers interest, repayment schedule, security, default and remedies. Use a note for simple debts and an agreement for anything structured.
Does a promissory note need a witness?
It is not strictly required, but witnessing costs nothing and makes the document far harder to dispute later. Two witnesses with names, signatures and addresses is the sensible standard.
Does a promissory note attract stamp duty in Nigeria?
Yes. Promissory notes are stampable instruments, and an unstamped one can face difficulty being admitted in evidence until the duty and any penalty are paid. Stamp it at the outset.
Can I charge interest on a promissory note?
Yes, provided the rate is stated clearly in the note itself. If nothing is said about interest, the note is simply a promise to repay the principal.