When foreigners become involved in a civil dispute in Thailand, documentary evidence in Thai civil cases often decides who wins or loses. Whether the dispute is about a loan, a lease or a business contract, the way you prepare and present documentary evidence in Thai civil courts is just as important as what the documents say.
In Thai civil procedure, “documentary evidence” is not just “pieces of paper”. It covers any recorded medium that expresses information or intention, such as written contracts, letters, receipts and other records. Thai law treats documentary evidence as highly reliable, often more reliable than human memory.
Because of that, the Civil Procedure Code sets special procedural rules for using documents as evidence, rules that are stricter than those for ordinary witness testimony. If these rules are not followed properly, the court may refuse to consider your documents at all, even if they are 100% genuine.
This article explains, in practical English, the 5 core principles about documentary evidence in Thai civil cases, based on the Thai Civil Procedure Code. It is designed for non-Thai clients, business owners and in-house counsel who need to understand the process, not just the theory.
1. Documentary Evidence in Thai Civil Cases: The “Golden Rule” of Original Documents
Under the Thai Civil Procedure Code, when a party relies on a document as evidence, the default rule is that the court expects to see the original document, not just a copy.
Why? Because the original gives the court the best chance to detect:
- Alterations or erasures
- Different inks or handwriting
- Authentic signatures, stamps and seals
A simple photocopy or PDF print-out is much easier to manipulate and therefore carries less evidential weight, unless it falls under an exception.
1.1 Exceptions: When can a copy be used?
Thai law recognises that sometimes the original is unavailable for reasons beyond your control. In those situations, the court may allow the use of a copy or even oral testimony in place of the original document. The main scenarios include:
- All parties agree to use a copy
- If both sides accept that a particular photocopy or scan is accurate, the court may rely on it without requiring the original.
- Original destroyed or lost due to force majeure or circumstances beyond control
- For example: fire, flood, accidental destruction, not intentional destruction by the party relying on it.
- The party must prove to the court that the loss was not their fault and that they tried reasonably to locate the original.
- Original in the hands of a third party or government agency and difficult to obtain
- When the original is under the custody or control of an authority or third party, and practically difficult to bring to court, the court may admit properly certified copies instead.
- Official documents with certified true copies
- If a responsible official has certified a copy as true and correct, Thai law often treats this as sufficient for evidentiary purposes unless the court orders otherwise.
In all these cases, the key idea is: the court must be satisfied that using a copy is necessary and fair in the circumstances.
2. Before Trial: Witness List and Document Copies Must Be Filed in Advance
Many foreign litigants are surprised to learn that, in Thai civil cases, you cannot simply “show up on the trial date with your bundle of documents”. There is a pre-trial procedure that must be followed.
2.1 Filing the witness list
Before the date for taking evidence, each party must file a witness list that specifies the evidence it intends to rely on, including:
- Names of witnesses (witnesses of fact, expert witnesses, etc.)
- A list of documents that will be used as evidence
Failure to include a document in this list can result in serious procedural risk: the judge may refuse to allow you to use that document later (unless you can show a good reason and obtain the court’s permission).
2.2 Serving copies on the opposing party in advance
Thai civil procedure is based on fairness and the right to prepare a defence. Therefore, copies of documentary evidence listed in your witness list must also be served on the other side in advance, commonly 7 days before the hearing, subject to the court’s order.
If you fail to provide copies in time, the court may:
- Refuse to admit the document as evidence; or
- Postpone the hearing and possibly order you to bear the additional costs, unless there is a reasonable excuse.
For foreign parties, this has practical implications:
- You must gather and organise your documents early.
- You should coordinate with your Thai lawyer about translations (if needed) and certification, because these also take time.
3. No Oral Evidence Instead of Required Documentary Evidence (Section 94 CPC)
One of the most important rules, and one that frequently surprises non-Thai litigants—is that oral testimony cannot normally replace documentary evidence when the law requires a written document.
A common example is a loan agreement:
- Under the Civil and Commercial Code, certain contracts, such as loan agreements over a specified monetary threshold, must be in writing.
- In such cases, the court expects to see the written document itself to prove the existence and terms of the contract.
3.1 What does this mean in practice?
If the law requires a written contract and you go to court without the document, you generally cannot rely on witness testimony alone to prove:
- That the contract existed, or
- That the agreed terms were different from what appears in the written document
Put simply:
Once something is put into writing, you cannot usually contradict or change it later by “free-style” oral testimony.
3.2 Limited exceptions
This does not mean oral evidence is always irrelevant. Parties may still use oral evidence to support arguments that:
- The document is forged or not genuine
- The contract is void or voidable (e.g. lack of capacity, fraud, duress, mistake)
- The other party has misinterpreted the meaning of the document
But these are specific legal allegations and must be pleaded and proven properly. The general rule remains: if the law says the deal must be in writing, the document comes first.
4. Stamp Duty: A Tax Issue That Can Destroy Your Evidence
Another “trap” for civil litigants is stamp duty under the Thai Revenue Code.
Certain documents, such as loan agreements, leases of immovable property, powers of attorney and other specified instruments, are subject to stamp duty. If these documents are not duly stamped in accordance with the tax law (both in terms of amount and cancellation of the stamp), they may not be admissible as evidence in civil proceedings until the deficiency is cured.
4.1 Practical consequences in civil cases
In practice, if:
- A contract that should bear stamp duty is unstamped or under-stamped, and
- A party tries to rely on it as evidence in a civil case,
the court may initially refuse to accept the document as evidence until the proper duty (and any applicable surcharge or penalty) has been paid at the Revenue Department. In serious cases of non-compliance, the court might treat the document as if it does not exist for evidentiary purposes.
This can be devastating in:
- Loan disputes
- Lease disputes
- Disputes over guarantees or powers of attorney
because these types of documents are often central to the case.
4.2 What should litigants do in practice?
While we cannot provide case-specific advice, as a general educational point:
- Parties should ensure that key contracts are properly stamped at the time of execution.
- If a dispute arises and litigation is likely, your Thai lawyer will normally review the stamp duty status and, if necessary, assist in regularising it with the Revenue Department before relying on the document in court.
5. Objecting to Documentary Evidence (Section 125 CPC)
What if the other side produces a document that you believe is fake, inaccurate or misleading?
Thai civil procedure provides a mechanism for objection to documentary evidence.
5.1 Timing is critical
If you want to challenge the authenticity or correctness of a document, you must:
- Object before the documentary evidence procedure is completed, in practice, this usually means during the stage when the document is being produced and admitted, not months later.
If you fail to object in time, the law presumes that:
- The document exists
- It is genuine
- Any certified copy is correct
and you may lose the chance to attack these points later.
5.2 What can you object to?
Typical grounds include:
- The document is forged or has been materially altered
- The document is not signed by the person who is alleged to have signed it
- The copy does not accurately reflect the original
- The document was not properly executed or is otherwise invalid
The court retains power to investigate authenticity on its own initiative, but as a party, you should assume that if you remain silent, you accept the document.
6. Why Documentary Evidence in Thai Civil Cases Is So Important
These rules might sound technical, but they have very real consequences in Thai civil litigation:
- A creditor with a perfectly valid loan may lose a case because the original document is missing and the court refuses to rely on copies.
- A tenant may lose a lease dispute because the lease is unstamped and not regularised before trial.
- A party may be stuck with a document’s wording because they did not object to its authenticity or did not follow the proper procedure to challenge it.
In summary:
- Originals first – always try to preserve and present original documents.
- Follow pre-trial procedure – file your witness list and serve copies in time.
- Respect the “no oral evidence instead of documents” rule for contracts that must be in writing.
- Check stamp duty on key contracts early.
- Object to bad documents promptly or risk being deemed to accept them.
Because these procedural rules can make or break a civil case, parties should treat documentary evidence and its procedural handling as a strategic priority, not an administrative afterthought.
FAQ: Documentary Evidence in Thai Civil Cases
1. What counts as “documentary evidence” under Thai law?
“Document” under Thai law covers paper and other materials on which information is recorded by letters, numbers, diagrams or other symbols, and which can serve as evidence of their meaning. In practice, this includes contracts, letters, receipts, invoices, corporate records and many official forms. Electronic records may also be recognised under separate legislation.
2. If the original contract is lost, can I still sue in Thailand?
Possibly, but it is more complicated. The court may allow copies or oral evidence only if you prove that the original was lost or destroyed through no fault of your own, or that it is impracticable to produce it (for example, it is kept by an authority and cannot reasonably be brought to court). The court has discretion, and you should expect a higher evidential burden.
3. Is a simple photocopy of a contract enough to win a civil case?
Not by itself. A photocopy can be acceptable if:
- The other party does not dispute it, or
- It falls within an exception where the court allows copies (e.g. official certified copies, documents difficult to produce, or originals destroyed without fault).
If authenticity is disputed, the court will typically expect stronger proof, and may require the original or additional supporting evidence.
4. Can witnesses testify that the “real agreement” was different from the written contract?
Generally no, if the law requires the contract to be in writing. In such cases, the written document is the primary evidence of the parties’ agreement, and witnesses cannot normally contradict its terms. Witnesses can, however, testify about issues such as forgery, mistake, fraud, duress or misinterpretation, if those issues are properly raised.
5. How do I object to a document I believe is forged?
You must object during the document-admission stage, before the evidence is fully taken. Your lawyer will usually state the objection on the record and may ask the court to order forensic examination, summons of relevant officials, or other measures. If you wait too long, the law may treat you as having accepted the document’s authenticity.
6. What happens if my contract is not properly stamped with Thai stamp duty?
If the document should bear stamp duty under Thai tax law but is unstamped or under-stamped, the court may refuse to admit it as evidence until the deficiency is cured, usually by payment of duty and any surcharge at the Revenue Department. If the issue is not corrected, the document may effectively be unusable as evidence, which can severely harm your case.
Get Strategic Advice on Documentary Evidence in Thai Civil Litigation
Documentary evidence in Thai civil cases is not just about “having the documents”. It is about:
- Having the right documents
- In the right legal form
- Properly stamped
- Timely disclosed and
- Correctly handled in court procedure
If you are a foreign individual, investor or company facing a civil dispute in Thailand, whether over a loan, lease, shareholder agreement, guarantee or other contract, it is essential to have a Thai litigation team that understands both the substantive law and the procedural rules on evidence.
Lex Bangkok assists foreign clients in:
- Reviewing and organising documentary evidence
- Assessing risks related to missing originals or stamp duty
- Preparing witness lists and evidence bundles
- Strategically objecting to defective or forged documents
For tailored advice on your specific situation, we strongly recommend arranging a consultation with a qualified Thai lawyer at Lex Bangkok before you commence or respond to court proceedings.
info@lexbangkok.com