Section 94 — Oral evidence may not vary documents
Statutory text (Thai original)
เมื่อใดมีกฎหมายบังคับให้ต้องมีพยานเอกสารมาแสดง ห้ามมิให้ศาลยอมรับฟังพยานบุคคลในกรณีอย่างใดอย่างหนึ่งดังต่อไปนี้ แม้ถึงว่าคู่ความอีกฝ่ายหนึ่งจะได้ยินยอมก็ดี(ก) ขอสืบพยานบุคคลแทนพยานเอกสาร เมื่อไม่สามารถนำเอกสารมาแสดง(ข) ขอสืบพยานบุคคลประกอบข้ออ้างอย่างใดอย่างหนึ่ง เมื่อได้นำเอกสารมาแสดงแล้วว่า ยังมีข้อความเพิ่มเติม ตัดทอน หรือเปลี่ยนแปลงแก้ไขข้อความในเอกสารนั้นอยู่อีกแต่ว่าบทบัญญัติแห่งมาตรานี้ มิให้ใช้บังคับในกรณีที่บัญญัติไว้ในอนุมาตรา
(๒) แห่งมาตรา ๙๓ และมิให้ถือว่าเป็นการตัดสิทธิคู่ความในอันที่จะกล่าวอ้างและนำพยานบุคคลมาสืบประกอบข้ออ้างว่า พยานเอกสารที่แสดงนั้นเป็นเอกสารปลอมหรือไม่ถูกต้องทั้งหมด หรือแต่บางส่วน หรือสัญญาหรือหนี้อย่างอื่นที่ระบุไว้ในเอกสารนั้นไม่สมบูรณ์หรือคู่ความอีกฝ่ายหนึ่งตีความหมายผิด
English translation
When the law requires a document as evidence, the court shall not admit oral evidence in any of the following cases, even though the other party consents:
(a) to adduce oral evidence in place of documentary evidence when the document cannot be produced;
(b) to adduce oral evidence in support of an allegation that, after the document has been produced, there are still additional, deleted, or altered statements to the text of that document.
However, the provisions of this section do not apply in the case provided in subsection (2) of Section 93, and shall not be deemed to deprive a party of the right to allege and to adduce oral evidence in support of an allegation that the documentary evidence produced is forged, or is incorrect in whole or in part, or that the contract or other obligation stated in that document is not complete, or that the other party has misinterpreted it.
This English translation is provided for reference only and has not yet been firm-verified — always rely on the Thai original.
Firm annotation
Section 94 is Thailand's parol evidence rule. Where substantive law requires a matter to be proved by a document, oral evidence cannot substitute for the missing document (a) or vary its text by adding, cutting, or altering (b). The final paragraph preserves important escape routes: the rule does not bar oral evidence that a document is forged or incorrect, that the contract or obligation it records is not complete, or that it is misinterpreted, nor does it apply to the Section 93(2) situation of an original lost or destroyed without fault. It is closely tied to substantive requirements in the Civil and Commercial Code, such as the writing requirement for loans, and is frequently invoked in loan, guarantee, and sale disputes.
Why this matters in practice
This rule regularly decides loan and contract cases: if the written agreement says one figure, you usually cannot testify that the real figure was different. The practical answer is to attack the document itself where the facts allow, that it is forged, incomplete, or that the underlying obligation never became effective, because those arguments fall within the last paragraph. Draft and keep documents carefully, and if a written contract is wrong, seek advice before trial on whether your challenge fits an exception.
Supreme Court decisions interpreting this section
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Supreme Court Judgment No. 6656/2567 (2024)
Adducing oral testimony to show that the loan amount in a written loan agreement was later altered is barred under Section 94 paragraph one (b) as evidence that varies the text of the document.
The Supreme Court held that the plaintiff's oral evidence that the loan figure had been changed after signing could not be admitted under Section 94(b), so only the amounts supported by writing could be claimed.
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Supreme Court Judgment No. 4209/2566 (2023)
The last paragraph of Section 94 preserves a party's right to adduce oral evidence in support of an allegation that the contract or obligation stated in the document is not complete.
The Supreme Court held that where the defendant contended the debt was not complete, he was entitled to adduce oral evidence in support under Section 94 last paragraph, considering the sequence of the money transfer and the loan agreement.
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Supreme Court Judgment No. 2451/2567 (2024)
While Section 94 last paragraph allows oral evidence that an obligation is not complete, a party relying on a public document also benefits from the Section 127 presumption of authenticity, placing the burden on the party alleging incompleteness.
The Supreme Court noted that although Section 94 last paragraph permits proof that a loan obligation is not complete, a registered mortgage as a public document is presumed genuine under Section 127, so the defendant asserting incompleteness bore the burden.
Curated decisions with case numbers verified against the Supreme Court database. English renderings are the firm's editorial translation for study.
Frequently asked questions
Can I testify that the written contract amount is wrong?
Generally no. Where the law requires a document, Section 94(b) bars oral evidence that adds to, cuts, or alters the text, even if the other side agrees.
When can I still use witnesses about a document?
The last paragraph lets you adduce oral evidence that the document is forged or incorrect, that the contract or obligation is not complete, or that it was misinterpreted, and the bar does not apply to lost originals under Section 93(2).