Certified True Copies in Thailand: Can You Sign Them Online?

The short answer: it depends on who's receiving the document, not on one single rule that applies everywhere. Most articles you'll find online only answer half the question. Some just say "yes, sign it online" without citing any legal basis. Others explain in detail how to write it out by hand on paper, without mentioning the digital option at all.

This article answers straight, case by case: which situations can use an electronic signature instead, which situations still require the real thing written by hand, and how to certify a copy correctly no matter which route you choose.

TL;DR: There's no single law that dictates the format for writing "certified true copy." It's a requirement set by each receiving institution individually (banks, the Land Department, government agencies), used to confirm identity and prevent forgery. For ordinary business documents between private parties (contracts, quotations, consent forms), an electronic signature under the Electronic Transactions Act B.E. 2544 (2001) works as a substitute. But for institutions that still require the certification to be handwritten across the document with a stated purpose, a digital signature may not yet be accepted until that institution formally announces it will accept one. This article explains what actually works, what still requires waiting, and how to certify a copy safely no matter which route you take (not legal advice).

What You'll Get From This Article

• There's no single law that dictates the format for a "certified true copy"; it's a requirement set by each receiving institution individually.
• Business documents between private parties (contracts, quotations, consent forms) can be signed electronically instead, under the Electronic Transactions Act B.E. 2544 (2001).
• Some institutions still require a handwritten certification across the document; check with that institution directly before going digital.
• 5 things to do when certifying a paper copy, to reduce the risk of it being misused.
• Document forgery is a criminal offense under the Criminal Code.
• This article is not specific legal advice.

What Exactly Is a "Certified True Copy," and Who Sets the Format?

"Certified true copy" isn't a requirement set by any one specific law; it's a requirement each receiving institution sets on its own, whether that's a bank, a government agency, or an employer, to confirm that the submitted copy matches the original, and to prevent the copy from being misused.

A survey of real-world practice across several independent sources consistently found the same pattern: writing "certified true copy" along with a signature on a copy of an important document, such as an ID card or house registration, is a commonly used practice, not a requirement backed by any single law.

Can You Certify a True Copy With an Electronic Signature?

Yes, for documents exchanged between private parties, such as contracts, quotations, consent forms, or internal organizational agreements. An electronic signature carries the same legal weight as a handwritten signature under the Electronic Transactions Act B.E. 2544 (2001), as long as the signing method used is reliable and can be verified afterward.

That reliability is measured by identity-verification measures such as OTP and a record of any changes to the document (audit trail). These strengthen evidentiary weight, they are not a 100% guaranteed legal outcome. Every case depends on its own specific facts and the judgment of the court or the relevant institution.

Read the full guide on the legal validity of electronic signatures

When Do You Still Need the Real Thing or an Institution's Specific Method?

Some government agencies or financial institutions still require a paper copy certified by hand, with the specific wording they require, as long as that institution hasn't clearly announced it will accept a digital format.

The safest approach is to check directly with the institution you're submitting the document to, before assuming a digital method will work. Don't assume every institution accepts an electronically signed copy, since each one has its own criteria that can change.

How to Write "Certified True Copy" on Paper Safely

These 5 steps reduce most of the risk of a copy being misused:

1. Only photocopy the front of the card. Don't copy the back unless necessary, since the information on the back is usually not needed to verify identity in most transactions.
2. Draw an X across the document so there's no blank space that could be filled in with other text later.
3. State the purpose clearly in brackets, such as "for opening a bank account only," to limit its use for anything else.
4. State the date the copy was certified, so it can be verified later when the copy was made.
5. Sign so your signature crosses over the document itself, not in a blank space that could easily be separated from the document.

These principles apply even when a paper copy is still required, and they help protect you no matter which route you end up choosing.

The Risk if a Copy Is Forged or Incorrectly Certified

A copy that isn't adequately protected can be misused without the owner even knowing. Forging or altering a document is a criminal offense under the Criminal Code, under the offense of document forgery.

Sections 264-265 of the Criminal Code, covering the offense of document forgery and forgery of instruments of title, are the relevant offense when a copy is forged or altered without authorization. This is exactly why you should follow the 5 steps above every time you certify a copy, whether it's a paper copy or a digital file.

What About Your Company's Business Documents (Contracts, Consent Forms)?

For business documents exchanged with customers or partners, as opposed to personal business with a government agency, an electronic signature with an audit trail is a genuinely workable option: faster, verifiable, and legally valid under the Electronic Transactions Act B.E. 2544 (2001).

Unlike certifying a copy of an ID card, which has to follow each institution's own requirements, a contract or consent form between private parties is something the two parties can agree on themselves, with the law already backing the validity of an electronic signature.

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Conclusion

There's no single answer that works for every case; it depends on who's receiving the document. For business documents between private parties, contracts, quotations, or consent forms, an electronic signature is a genuinely workable option. For personal business with a government agency, check directly with that institution before going digital.

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This article is general information, not specific legal advice for your situation. Consult a legal advisor before making a decision in a high-risk case.

Last updated: August 2026. This article is reviewed for changes in institutions' practices at least once a year.