Signing Company Contracts Online: What Evidence Is Needed to Prove Them?

Signing Contracts Online Is Valid — But You Have to Make It Provable

Thai law does not require every business contract to be signed with a pen. The Electronic Transactions Act B.E. 2544 (amended several times, including the 3rd and 4th amendments, B.E. 2562) already recognises contracts made as electronic data and electronic signatures. The real problem for a company is usually not "is it valid?" but, when a dispute arises, can it be proved who signed, in what capacity, and that the document is still the original version?

This article is written for Thai companies and companies with foreign shareholders that sign B2B contracts through online systems. It is divided into what the law requires and what we recommend doing in addition as good practice.

Who has the authority to sign on behalf of a company?

Authority does not change simply because a signature is made online. A Thai company is bound by the authorised directors as registered in the company certificate. Whether it requires one director signing alone, two directors signing jointly, or a signature together with the company seal, it must be done in that way.

Before sending an online signing envelope, check 4 things:

1. The name of the signer matches an authorised director in the latest company certificate.
2. If joint signatures are required, the system must allow all the required directors to sign — not one signing on another's behalf without a power of attorney.
3. If a manager or employee is to sign, there must be a power of attorney that clearly sets out the scope of authority.
4. Request the counterparty's recently issued company certificate, and keep it with the contract.

For details on the registered signing mandate, company certificates, and powers of attorney, read on at Who can bind your Thai company. This article will not repeat them.

How to Verify the Signer's Identity

Section 9 of that Act provides that the method used must identify the owner of the signature and show the signature owner's intent regarding the text of the document; only then is a signature considered to have been made.

Typing a name at the end of an email or drawing a signature on screen with nothing further to confirm it is therefore the weakest form of evidence. What helps make it provable is a practice we recommend, not a requirement.

• Send the signing link to the company email the director actually uses, and have the system record the IP address, date and time, and device.
• Use two-step authentication, such as a one-time password.
• For high-value contracts, check the signer's ID card or passport against the company's certificate of incorporation.
• Also keep the email or message in which the signer confirms that they intended to sign this version.

How many types of electronic signatures are there, and which one is considered reliable

The law does not set out fixed categories by name, but there are two layers to understand.

Section 9 requires reliability to be considered from several factors, such as the security of the identity-verification method, the nature and value of the transaction, commercial practice, and the rigour of the communication system. A high-value contract should therefore use a stricter system than a minor day-to-day sale and purchase contract.

Section 26 does not require every contract to be in this form, but when the specified characteristics are met, the law treats it as a reliable signature, and the other party may still present evidence to show that it is not reliable. Digital signatures bound to a certificate most easily meet these characteristics.

Company Seal: Can a Director's Signature Be Used Instead?

If the company certificate specifies that directors must sign together with affixing the company seal, you must check whether the online signing covers both elements.

According to the ETDA article on electronic seals of juristic persons:

• An electronic seal is possible, because Section 9, final paragraph, applies the rules on electronic signatures to the sealing of juristic persons by analogy. It must be possible to identify which juristic person the seal belongs to, and to show the intention of the juristic person.
• The law does not prescribe a specific technology for seals.
• A director's electronic signature cannot be used instead of a seal, because the first is linked to a person and the latter to a juristic person.

In practice, if the company must have a seal, ask for the signing system to support electronic sealing, or affix an image of the company seal together with evidence of who approved it. If you are unsure whether the company is bound by a seal, check the company certificate first. Do not guess.

How to store contract files so they can be used as evidence

The law sets out principles on the storage and use of evidence.

• Original (Section 10) — A document is deemed to have been presented or stored in its original form if a reliable method is used that preserves the accuracy of the text from the moment it is created, and the text can be displayed again afterwards.
• Storage (Section 12) — The information must be accessible and retrievable without any change of meaning, be in a form that displays the text accurately, and retain the source, the destination, and the date and time of transmission or receipt, if any.
• Evidence (Section 11) — Electronic data may not be refused admission as evidence merely because it is electronic data, but its weight depends on the reliability of the method of creation, storage and identification of the sender.

These sections do not set a contract retention period directly. The period depends on specific laws, such as accounting and tax laws, and on the limitation period of the dispute. Contracts should therefore be kept throughout the contract term and for the period during which a claim can still be filed.

Items that should be kept together (recommended practice)

1. The fully signed contract file, together with the file issued by the system in its original format, not only a scanned image.
2. The signing log (audit trail) showing who signed, when, and from which address.
3. The company certificate and the power of attorney as at the date of signing.
4. Emails or messages used to agree the terms and to send the contract.
5. Backup copies in storage that does not depend on a single signing provider, in case the account is closed or the provider ceases operations.

If it is printed out for use, the final paragraph of Section 10 states that a printout may be used in place of the original when the text matches the electronic data and it is certified by an agency designated by the Electronic Transactions Commission. Printing it out yourself is therefore not the same as the original.

Do Electronic Contracts Require Stamp Duty?

Stamp duty is collected under the Revenue Code on the instruments listed in the stamp duty tariff schedule. Producing an instrument as a file does not exempt it from duty, but Section 8, paragraph two of the Revenue Code provides that an instrument is deemed stamped if payment is made on its behalf or the process is carried out by electronic means in accordance with the criteria announced by the government agency concerned.

The Revenue Department provides an e-Stamp Duty service for electronic instruments (แบบ อ.ส.9 — Form O.S.9) on its website, and the current service page supports both electronic and paper instruments, according to information that can be verified with the Revenue Department.

• When the Department issues a certification code for the duty paid together with a receipt, the instruments listed on the form are deemed fully stamped.
• When the system was introduced, the instruments supported at first were 5 types: hire of work, loan or overdraft, power of attorney, proxy for a company meeting, and guarantee. The Department later opened the system to more, so the latest list in the system should be checked.
• The deadline stated in the Department's documents is: pay before the instrument is made, or within 15 days from the day following the date the instrument is made, counting public holidays.
• Filing late incurs a surcharge as notified by the Department, and an instrument that is not fully stamped cannot be used as evidence in a civil case until the duty is paid.

On rates and exempt instruments, we have not stated figures in this article because they can change; check with the Revenue Department before entering into an actual contract.

Which contracts still cannot be signed online alone

The Electronic Transactions Act applies to civil and commercial transactions, but there are limitations.

1. Transactions exempted by royal decree — The Royal Decree B.E. 2549 provides that transactions relating to family and succession are not subject to this Act, for example a will.
2. Transactions that specific laws require to be registered with an official — for example, the sale and purchase of immovable property must be made in writing and registered with the competent official, otherwise it is void (Section 456 of the Civil and Commercial Code), and a lease of immovable property for more than three years that is not registered can be enforced by action for only three years (Section 538).
3. Registration with government agencies — for example, changing a company's registered particulars must follow the system and documents prescribed by that agency.
4. Consumer protection law — Section 3, paragraph two, of the consumer protection law states that it does not affect laws enacted to protect consumers.

Share purchase agreements, agreements requiring cross-border notarisation, or agreements with government agencies may have their own specific procedures. We do not summarise them as a list in this article; each case should be checked individually.

If You Have Already Signed and Are Worried the Evidence Is Not Enough

1. Save the file and the signing record from the system immediately, before the account expires or the link is deleted.
2. Check whether the signer is listed in the authorised signatory register in the company certificate as at the date of signing.
3. Check whether the contract requires stamp duty, and whether it can still be paid in time.
4. If you find a problem with the signer or the authorised signatory register, have that party's company ratify the original contract by a letter of ratification, signed by a director authorised under the authorised signatory register, with the company seal affixed if required.
5. Consult a lawyer before sending a demand letter or filing a lawsuit, so that the electronic evidence can be prepared in advance.

Pre-Signing Checklist for Online Contracts

1. Whether the signer appears in the signature list under the company's certificate of incorporation, or holds a power of attorney.
2. Whether a seal must be affixed, and whether the system supports electronic seals.
3. Whether the signing system verifies the signer's identity and records the date and time.
4. Whether the system can detect that the file has been altered afterwards.
5. Whether the contract is of a type that must be registered or executed in a special form.
6. Whether the contract is subject to stamp duty, and the deadline for payment.
7. Keep the file, the signing record, and the supporting documents in a secure place together with backup copies.

Read more

• Who has the authority to bind your Thai company: directors, authorised signatories and the company affidavit
• Making a business contract airtight: 6 points to check before signing
• Which documents need a lawyer's certification, and whether the destination will accept them once certified
• Services: Drafting and reviewing contracts and business documents
• Services: Corporate secretarial work and change registrations