Case study: certifying signatures on a cross-border business contract

The situation

A Thai business entering a distribution agreement with an overseas partner

The overseas partner asked for the Thai side’s signatures to be certified before performance began.

What actually blocked the file

• The draft still had unfilled date and quantity fields.
• The company signer had no evidence of signing authority on hand.
• The parties thought certification means the contract terms were reviewed.

The sequence we ran

1. Finalised the text and filled or struck through unused fields.
2. Prepared the company affidavit and evidence of signing authority.
3. Explained that certification evidences signing, not the contract terms.
4. Had the authorised signatories sign before the attorney and archived the originals.

Outcome

The partner received verifiable evidence of signing, and both sides shared the same understanding of what the certification covers.

What to prepare for contract signature certification

• The signer’s valid original passport or Thai ID card.
• Written confirmation from the receiving authority of which certification is required and whether onward legalisation is needed.
• The finalised contract, agreed by all parties and still unsigned.
• Identity documents for every signatory who will sign before the attorney.
• A company affidavit and evidence of signing authority where a party is a company.
• A power of attorney and the agent’s ID, where a representative handles steps that legally permit representation.
• Any additional copies specifically required by the receiving authority in your case.

This list reflects the requirements published by the responsible authority on the verification date. Authorities may change their conditions, so confirm with the source before lodging. Lawyers Council of Thailand (Lawyers Act B.E. 2528, section 27) · 2026-08-16 · source

How contracts and cross-border agreements are notarised

1. Confirm with the receiving authority which certification is required — signature certification, certified true copy, or certification of facts — because the wording differs for each.
2. Check that the attorney is registered with the Lawyers Council as a Notarial Services Attorney and holds a verifiable registration number.
3. Verify that every party has signing authority and that the governing law is stated clearly.
4. Prepare the contract bilingually and state which language version prevails in case of conflict.
5. The parties initial every page and sign the execution block before the attorney.
6. The attorney signs, seals, and records the notarial registration number and date on the certification.
7. For overseas use, take the notarised document for legalisation at the Department of Consular Affairs and then, where required, at the destination country’s embassy or consulate.

The steps below are drawn from the procedures the responsible authority publishes itself, with the source and verification date shown. Some steps depend on the case and may change with the authority’s own announcements. Lawyers Council of Thailand (Lawyers Act B.E. 2528, section 27) · 2026-08-16 · source

Why certified company documents are still returned

The company affidavit is older than the destination accepts

Many destinations set their own recency limit for a company affidavit. Where an older extract is used, obtain a fresh one from the Department of Business Development before certification.

The signer is not an authorised director per the affidavit

Signing authority must match the affidavit’s conditions, such as two directors signing jointly or affixing the seal. Signatures that do not satisfy them are returned for re-execution.

No resolution supports the signature

For certain transactions, such as granting authority or transferring rights, the destination may require the approving resolution to be attached, and will request it if absent.

The document was signed before meeting the attorney

Signature certification confirms that the signer signed in the attorney’s presence. If the document arrives pre-signed, the attorney will ask for a fresh copy to be signed in person.

Identity document is expired or presented only as a copy

Identity verification requires a valid original passport or ID card. A copy or an expired document is not sufficient, and the certification waits until a valid original is produced.

The certificate wording does not match what the destination prescribes

Many receiving bodies prescribe their own certificate wording. Generic wording is commonly returned with a request to re-execute using the prescribed form.

The document still contains blanks or unfilled fields

The attorney certifies the document as it stands at that moment. Blanks that could be completed later should be filled in, or struck through, before signing.

Lawyers Council of Thailand (Lawyers Act B.E. 2528, section 27) · 2026-08-16 · source

What to watch next time

• Finalise the contract before the signing appointment.
• Always bring evidence of signing authority.
• Signature certification is not an endorsement of the terms.

Questions this case raises

Must both parties sign together?

No — each may sign before an authorised certifier in their own country, and the counterparts are then combined as agreed.

Should every page be initialled?

It depends on the agreement and the destination; initialling each page is common to prevent page substitution.

Related reading

• Case study: certifying a Thai power of attorney for property abroad
• Case study: a single-status declaration for marrying abroad
• Case study: swearing an affidavit of single status for a marriage abroad
• Case study: certified passport copies for an overseas institution
• Notarial Services Attorney
• Consular legalization