Thailand Company Formation for Foreigners — The 2026 Structuring Guide

The five vehicles at a glance

Every foreign-controlled Thai operation uses one of these — pick before drafting the AoA:

• Standard Thai Ltd (49/51) — Thai majority shareholders, no restricted activities, THB 2M capital per foreign work permit
• BOI-promoted Ltd — 100% foreign ownership permitted, corporate tax holiday 3–8 years, quota for skilled foreign hires
• US Treaty of Amity — 100% US ownership, no BOI benefits, blocked from land ownership and a short list of reserved sectors
• Foreign Business License (FBL) — case-by-case Cabinet approval, THB 3M capital, 6–12 month timeline, rarely granted
• IEAT / EEC zoned company — 100% ownership inside industrial estates, streamlined work permits, land-use rights

The 49/51 nominee trap

The single most common mistake is using Thai 'nominee' shareholders — Thai nationals who hold shares on trust for the foreigner. Section 36 of the Foreign Business Act criminalises this: up to 3 years' imprisonment and forced divestment. The Department of Business Development actively audits companies with round-number Thai shareholdings that never file dividends. If you cannot run a genuine 49/51 with real Thai capital and voting rights, do not use this vehicle.

BOI — when it makes sense and when it doesn't

BOI is the strongest structure for tech, manufacturing, IHQ, and R&D. It grants 100% foreign ownership plus 3–8 years of corporate tax holiday, plus streamlined work permits at THB 1M capital each instead of THB 2M. But BOI requires substance: a real business plan, minimum project size (typically THB 1M investment excluding land), and reporting obligations every 6 months for the promotion life.

BOI is wrong for pure trading, real estate, restaurants, and most B2C retail — those categories are not on the promoted list. For those, use a 49/51 Thai Ltd (real Thai partners) or, if you are American, Treaty of Amity.

US Treaty of Amity — the American shortcut

The 1966 Treaty of Amity between Thailand and the US permits US citizens and US majority-owned companies to hold 100% of a Thai company across most sectors. It does not require BOI, has no tax holiday, but takes only 4–6 weeks and does not restrict you to a promoted activity list. It is blocked from communications, transport, banking, professional services (law/accounting), land ownership, and mineral exploitation.

You must prove US citizenship of every foreign shareholder (or majority US ownership of the shareholding entity), and register through the US Commercial Service in Bangkok before filing with DBD. Documents must be notarized and Apostilled in the US — this is where our cross-border service pillar comes in.

Capital, tax, and hiring reality

Regardless of vehicle, plan these upfront:

• Registered capital: THB 2M minimum per foreign work permit (THB 1M under BOI), fully paid up before applying
• 4 Thai employees per foreign work permit (2 under BOI), on formal SSO payroll
• Corporate income tax: 20% flat, or 15% on the first THB 3M for SMEs, or 0% during BOI holiday
• VAT registration mandatory at THB 1.8M annual revenue
• Annual audit and DBD filing regardless of size

Nominee shareholding — the structure that keeps collapsing

The most common structure sold to foreigners is also the most legally fragile: a 49/51 Thai limited company where the Thai majority shareholders are nominees holding on the foreigner's behalf. Section 36 of the Foreign Business Act B.E. 2542 prohibits a Thai national from holding shares as a nominee to enable a foreigner to operate a restricted business, and the penalties reach both the foreign beneficiary and the Thai nominees.

Enforcement is documentary rather than intuitive. The DBD looks for Thai shareholders who cannot evidence the source of funds used to subscribe their shares, share transfer instruments signed in blank and held by the foreign party, loan agreements from the foreigner to the Thai shareholders covering the exact subscription amount, and preference share structures that leave Thai shareholders with 51% of the capital but a negligible share of votes or dividends. Any of these on file turns a routine audit into an investigation.

A defensible Thai-majority company therefore requires Thai shareholders who genuinely paid for their shares from traceable funds and who exercise real rights. If that is not the commercial reality you want, the honest answer is that the 49/51 route is the wrong vehicle and BOI, Treaty of Amity, or an FBL is the structure to price out instead.

Post-incorporation compliance calendar

Incorporation is a two-week event; compliance is permanent, and the cost of getting it wrong is disproportionate to the amounts involved. Plan for the following recurring obligations from month one.

• Monthly withholding tax returns (PND.1, PND.3, PND.53) filed by the 7th of the following month, or the 15th when filed online
• Monthly VAT return (PP.30) by the 15th, once registered — filed even in months with no revenue
• Monthly Social Security contributions for every employee, filed and paid by the 15th
• Half-year corporate income tax estimate (PND.51) within two months of the end of the first six months of the accounting period
• Annual audited financial statements prepared by a licensed Thai CPA, approved at a shareholders' meeting within four months of year end
• Annual corporate income tax return (PND.50) and DBD financial statement submission within 150 days of year end
• Work permit and visa extension cycles for each foreign employee, with the 4:1 Thai employment ratio evidenced on SSO filings at the time of each renewal

Substance — what BOI and Immigration actually inspect

Both BOI promotion and work permit renewal now turn on operational substance rather than paperwork. Site visits are routine, unannounced, and specific: does the registered office exist as a working premises with a lease in the company's name, are the Thai employees on the SSO filings physically present and doing the roles described, does the payroll evidence match the bank debits, and is the business activity actually the promoted one.

Companies that fail these visits are usually not fraudulent — they are under-built. A virtual office address, four Thai employees who exist only on payroll, and a business activity that drifted away from the promoted category are enough to jeopardise a renewal. Build the substance before the first renewal cycle rather than in response to a visit notice.

Official sources

Company registration, shareholder filings, and annual financial statement submission are administered by the Department of Business Development at dbd.go.th. Investment promotion criteria, eligible activities, and the current incentive schedule are published by the Board of Investment at boi.go.th. Corporate income tax, VAT, and withholding obligations are set by the Revenue Department at rd.go.th. Work permits sit with the Department of Employment at doe.go.th, and social security registration with the Social Security Office at sso.go.th.

Capital thresholds, employment ratios, and incentive terms above reflect the position at the date shown on this page and are subject to change by regulation or Cabinet resolution. Approval of any application — BOI promotion, Foreign Business Licence, or work permit — is at the discretion of the reviewing authority. Nothing on this page is legal or tax advice for a specific structure.