Personal Loan Agreement Template Thailand (2026): Free Format + Interest Rules

Lending money to a friend, a relative, or a business partner in Thailand usually starts with trust and ends with an awkward silence. Not because people intend to default — but because nobody wrote down how much, when, at what interest, and what happens if it isn't paid. Six months later, "I'll pay you back after the season" has quietly become never, and the lender has nothing but a bank transfer record and a grievance.

A one-page written loan agreement (สัญญากู้ยืมเงิน) fixes this without killing the relationship. It forces both sides to agree on the numbers while they still agree on everything else. This guide gives you the standard format, explains the interest rules that trip up informal lenders (Section 654 of the Civil and Commercial Code does real work here), covers stamp duty, and sets out what you can actually do if the money doesn't come back.

Is a Loan Contract Between Individuals Legally Binding?

Yes — Thai law treats money loans between private individuals as fully enforceable contracts. Under the Civil and Commercial Code (CCC), a loan of money is complete when the lender transfers ownership of the money and the borrower agrees to repay an equivalent amount. No lawyer, no court filing, no registration required for the contract itself to exist.

What the written agreement adds is evidence. In practice, disputes between individuals turn less on what the law allows than on what either side can prove: the amount, the repayment schedule, the agreed interest, and any collateral. Bank transfers show money moved; they don't show whether it was a loan, a gift, an investment, or repayment of something older. The signed agreement closes that gap.

One evidentiary note: for smaller amounts, courts weigh oral testimony and transfer records together. For anything meaningful — say above a few tens of thousands of baht — attach a copy of the borrower's ID card and have both parties sign every page.

The Interest Rules Most Informal Lenders Get Wrong

This is where casual lenders create legal problems for themselves, so read this part twice.

Default rate: 5% per year

If your agreement says nothing about interest, the CCC's statutory default applies — 5% per annum. You can't claim more than that retroactively just because "everyone knows" the deal was richer.

Agreed rates: write them down, keep them lawful

Parties may agree on interest, but a rate above the statutory ceiling risks being cut down by a court to the lawful maximum, with the excess treated as already paid principal. Thai law has moved repeatedly on consumer-lending ceilings (special regimes apply to licensed personal loans under finance-business regulations), so the practical rule for private lenders is:

• Keep the agreed rate moderate and clearly documented.
• Don't structure "interest" as separate fees designed to dodge the cap — courts look through relabeling.
• When in doubt, charging the statutory-style single-digit rate keeps the contract unassailable and the friendship intact.

Compounding interest monthly ("interest on interest") also needs explicit agreement — it isn't implied.

The classic trap: collecting interest upfront

Deducting three months of interest from the amount handed over, then expecting full principal back, is exactly the arrangement courts re-characterize. If the borrower receives 90,000 baht but signs for 100,000, the paperwork contradicts reality — and reality tends to win.

Loan Agreement vs Promissory Note (ตั๋วสัญญาใช้เงิน)

People mix these up constantly. They're different instruments:

	Loan agreement (สัญญากู้ยืมเงิน)	Promissory note (ตั๋วสัญญาใช้เงิน)
Nature	A contract recording the whole deal	A negotiable instrument — a formal promise to pay
Governed by	Civil and Commercial Code	Bills of Trade Act
Best for	Documenting terms, schedules, collateral	Payment obligation that may be endorsed/transferred, often used with post-dated cheques in local practice
Detail captured	High — parties, schedule, security, events of default	Low — payee, amount, maturity

In common Thai practice, a lender often takes both: the agreement records the deal, and a promissory note (or post-dated cheque) provides a payment instrument tied to installments. That combination is fine — as long as the note's terms match the agreement rather than contradicting it.

Stamp Duty: The Step Everyone Forgets

Loan agreements are among the documents subject to stamp duty in Thailand — 0.05% of the loan amount, payable when the agreement is executed (typically by purchasing stamps from a revenue office or via e-stamping). Receipts for interest payments can carry their own duty depending on form and amount.

Practical guidance:

• Duty is modest — on a 500,000-baht loan, 0.05% is 250 baht.
• An unstamped agreement is not void, but it loses evidentiary value until duty plus penalty is paid — which is precisely when you need it most.
• Stamp within the deadline from execution; late stamping carries penalties.

If that sounds fussy for small family loans, remember the rule scales with stakes: tiny loans between relatives often skip stamping and rely on transfer records; meaningful sums deserve the stamps.

Copy-Ready Template Structure

LOAN AGREEMENT / สัญญากู้ยืมเงิน

Date: ____________________

LENDER: Name ______________ ID No. ______________
Address ______________________________________________
Phone ______________

BORROWER: Name ______________ ID No. ______________
Address ______________________________________________
Phone ______________

1. PRINCIPAL: Baht ____________ (in words: ____________),
   transferred on ____________ via ☐ bank transfer to account
   ____________  ☐ cash  ☐ other: ____________
   Borrower confirms receipt of the full amount.
2. PURPOSE (optional): ______________________________
3. INTEREST: ☐ None  ☐ ____ % per annum, calculated on the
   outstanding principal, payable [monthly / with principal].
4. REPAYMENT: ☐ Lump sum due ____________
   ☐ Installments: Baht ______ per month starting ________,
     total ___ installments. Payment schedule attached.
5. LATE PAYMENT: Overdue amounts bear additional interest of
   ____ % per annum until paid. Missed payments beyond a
   grace period of ___ days make the entire balance due.
6. SECURITY (if any): ☐ None  ☐ Post-dated cheques nos. ____
   ☐ Promissory note(s)  ☐ Guarantor: Name ______ ID ______
   ☐ Collateral: ______________________________________
7. EARLY REPAYMENT: Borrower may repay early; interest is
   calculated only to the date of actual repayment.
8. DEFAULT: If Borrower fails to pay when due and remains in
   default for ___ days after written demand, Lender may
   demand immediate payment of all outstanding amounts.
9. COSTS: Reasonable costs of lawful enforcement arising from
   Borrower's default are borne by Borrower.
10. GOVERNING LAW: Thai law. Jurisdiction: Court of _________.

Signatures (every page initialed):
Lender ____________ Date ________
Borrower ____________ Date ________
Witness 1 ____________  Witness 2 ____________

Attachments: copy of Borrower ID card ☐  payment evidence ☐
             installment schedule ☐

Two clauses deserve special attention. Clause 1's receipt confirmation turns the document into proof of disbursement, not just promise. Clause 6's guarantor option is the cheapest credit enhancement there is — a guarantor with visible income changes repayment behavior more than any clause about penalties.

What You Can Do If You're Not Repaid

The escalation path, in order:

1. Written demand (หนังสือทวงถาม). A dated letter — registered mail with acknowledgment or a messaging channel that preserves history — stating the amount owed, the missed dates, and a firm deadline. Many defaults end here: the letter signals you keep records.
2. Negotiated restructuring. A signed addendum rescheduling payments beats an unpaid original schedule. Courts view borrowers who negotiate in good faith more favorably than those who vanish.
3. Mediation. District-level dispute mediation is cheaper and faster than litigation and works well where the relationship matters.
4. Civil action. The civil court can order repayment plus contractual interest. General contract claims carry a ten-year limitation period under the CCC, so time pressure is lower than people fear — but evidence decay isn't.
5. Cheque route, if used. Where the borrower issued cheques as payment devices and a cheque bounces, criminal consequences attach to dishonored cheques under Thai law — which is why post-dated cheques remain common collateral in informal lending. Handle this carefully and take advice before threatening criminal process; misuse of that leverage creates its own liability.

What you should not do: visit the borrower's workplace or family to apply social pressure, publicly name-and-shame on social media, or retain anyone who suggests doing either. Defamation and coercion claims convert creditors into defendants remarkably fast.

Common Mistakes

• No receipt-of-funds clause. The agreement proves terms, not performance — confirm the transfer inside the document.
• Interest structured as "fees." Courts see through relabeling, and the restructured version is worse for the lender.
• Lending against a cheque alone. Cheques capture almost none of the deal terms; pair them with the agreement.
• Forgetting stamp duty on significant sums — fixable before enforcement becomes necessary, expensive after.
• Letting the guarantor sign last, unread. A guarantor who didn't understand the obligation is a dispute waiting for its day in court.

Creating and Signing Online

Draft the agreement once, reuse the format forever. With AiDocX you generate the draft from a short description (amount, schedule, interest), adjust the clauses, then send it for electronic signature — valid for agreements like this under Thailand's Electronic Transactions Act B.E. 2544. Every party gets a stored copy, which means "I lost my paper" stops being an argument six months from now.

FAQ

Does the agreement need to be notarized? No notarization requirement exists for validity. Signatures plus witnesses are enough; notarization mainly helps when enforcing abroad.

Can I charge 20% to a friend? You can agree on it; whether a court would let you keep it is another matter — excessive rates risk reduction to the lawful ceiling. Moderate rates get paid; extreme ones get litigated.

Is a LINE message saying "I'll pay you back on the 30th" enough? It's evidence of a promise, and better than nothing. It won't cover interest, security, default, or jurisdiction — everything you need precisely when things go wrong.

Do I need witnesses? Not legally required for the contract's existence, but two witnesses (with ID copies) materially strengthen the document in a he-said-she-said dispute.

The borrower wants cash only. How do I prove I gave the money? Have the borrower sign a receipt line inside the agreement confirming full receipt ("Borrower confirms receipt of the full amount"), ideally with their ID number written beside it.

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Write it down while everyone still likes each other. Generate a loan agreement draft and collect signatures online with AiDocX — plans start at $6/month.