Which authority decides or issues Affidavit Declaration?

Who decides Affidavit Declaration

Responsibility sits with the Department of Business Development (DBD), the Revenue Department, the Board of Investment (BOI) and the Department of Employment, depending on the filing. Each office reviews only what falls under its own mandate, and a stamp obtained out of order is normally rejected rather than accepted retroactively.

Where more than one office is involved, keep the originals together with every intermediate certification. Officers verify the chain, not a single page.

How company, tax, legal and expat services in Thailand works

Corporate filings in Thailand are split across several regulators. Incorporation and registered-object changes sit with the Department of Business Development, tax registration and filings with the Revenue Department, investment privileges with the Board of Investment, and work authorisation with the Department of Employment. A document accepted by one of them is not automatically accepted by another.

Foreign shareholding is governed by the Foreign Business Act, with separate treatment for BOI-promoted companies and for US nationals under the Treaty of Amity. Structure decisions therefore have to be made before incorporation, because changing them later means re-registering objects, capital and sometimes the work-permit quota.

Any foreign-issued corporate document (certificate of incorporation, board resolution, power of attorney, passport copy) must normally be notarised abroad, legalised or apostilled, then translated into Thai and certified before a Thai registrar will accept it.

Where Affidavit Declaration fits in the document chain

Documents connected with Affidavit Declaration move through a fixed chain: issuance, translation, certification and acceptance. Each link is verified against the previous one, which is why a missing intermediate stamp cannot be repaired at the final counter.

Because company formation, accounting and tax, legal advisory and expat support is assessed on paper, the safest working method is to prepare the complete set before approaching any office, then submit once with everything attached.

Evidence the reviewing officer looks for

An officer checks four things: that the original is authentic and current, that the translation is complete, that the certifications appear in the correct order, and that the person submitting is entitled to do so.

None of those four is a formality. A file that satisfies three of them is still returned, and the queue restarts from the beginning.

Working with IVC

IVC has handled company formation, accounting and tax, legal advisory and expat support since 2011 - more than fourteen years of files across translation, notarisation, consular certification and submission support. We prepare, check and track the chain; the decision always remains with the authority, and we never promise an outcome.

Fees depend on document type, language pair, volume and urgency, so they are quoted by our staff rather than published. Contact us by phone, LINE or email with a scan of the document and the destination, and you will get a written scope before anything starts.

Pre-submission checklist

• Carry identity documents for every named party and for the representative
• Keep receipts and reference numbers for each stage
• Scan the complete file exactly as submitted
• Allow for public holidays at each office in the plan
• Confirm in writing what the receiving authority accepts today
• Use the certified original or an officially sealed copy, never a plain photocopy
• Match the spelling of every name to the passport, letter for letter

Common pitfalls

• Treating one authority's acceptance as binding on another
• Starting the chain from an uncertified photocopy
• Omitting seal or annotation text from the translation
• Booking travel around an unconfirmed processing date
• Relying on an outdated checklist instead of the issuing authority's own page

Official sources

• Department of Business Development — Company registration
• The Revenue Department — Tax registration and filing
• Thailand Board of Investment — Investment promotion
• Department of Consular Affairs, Ministry of Foreign Affairs (Thailand) — Legalisation and Apostille services
• HCCH — Apostille Convention status table

Information reviewed as of August 2026.