Bilingual contracts in Thailand — choosing the governing language, dispute clauses and supporting documents

A bilingual contract should state which language prevails if the two texts conflict. Without that clause, a Thai court will interpret from the parties’ intent, which is a burden of proof you can avoid.

Even where English prevails, using the contract in a Thai court or filing it with a Thai agency still requires a Thai translation, and some agencies, such as land offices, register only on their own Thai-language forms.

Terms such as "best efforts", "indemnify", "consequential loss" and "termination for convenience" have no exact Thai-law equivalents. A literal translation can shift the legal meaning, so the reviewer should be a lawyer who reads both languages, not only a general translator.

Penalty clauses must sit within the Civil and Commercial Code, which allows a court to reduce a penalty it considers disproportionate.

Governing law and the court or arbitral forum. Thailand is party to the New York Convention on foreign arbitral awards, but foreign court judgments generally cannot be enforced in Thailand directly; a new action is needed, using the judgment as evidence.

Notices: state the address, email and language for notices and when they are deemed received, to avoid disputes about whether notice was given.

Withholding tax on payments abroad and any double-tax treaty that may reduce the rate; state which party bears the tax.

Personal data protection under the Personal Data Protection Act B.E. 2562 where the contract involves transferring data abroad.

Read the prevailing-language version in full first to understand the commercial intent, then compare clause by clause with the other language. Keep a table of points where meaning differs, and have both parties confirm the revised wording before initialling every page.

If the contract must be registered with a Thai agency, also check that agency’s form, because the registered form may carry more weight against third parties than the full contract.

A bilingual contract should state clearly which language prevails if the two versions conflict, and whether that applies to the whole contract or only certain parts. The clause should appear in both languages with matching meaning. Without it, parties may have to argue over the true meaning, adding risk and cost.

Even where English is stated to prevail, using the contract in a Thai court or with a Thai agency usually requires a Thai translation, and some agencies rely primarily on the Thai text, for example land rights registration. So the Thai version deserves the same careful review as the main version.

Problem terms include “indemnify”, whose Thai equivalent may not have the same scope; “best efforts” versus “reasonable efforts”, which impose different levels of duty; “terminate” versus “rescind”, which have different legal effects; “consequential loss”, which Thai law does not define directly; and “shall” versus “may”, which separate obligations from rights. Agree the meaning of key terms in the definitions clause.

Also check that figures, dates, currencies and proper names match in both versions, as small differences here often cause disputes.

Have the parties sign or initial every page of both versions, and check that anyone signing for a company has authority under its affidavit. Some contracts, such as leases, loans and hire-of-work agreements, require stamp duty under the Revenue Code; otherwise they may not be admissible as evidence in civil proceedings until the duty and surcharge are paid.

Parties may choose the governing law of a contract under the Conflict of Laws Act, but some matters always follow Thai law, such as rights over Thai real estate and rules of public order. Choosing foreign law may mean having to prove that law before a Thai court later.

If arbitration is chosen, state the institution, seat, language and number of arbitrators clearly. Thailand is a party to the New York Convention, so awards from contracting states may be enforced in Thailand under the Arbitration Act, whereas foreign court judgments generally cannot be enforced in Thailand directly.

Many people think that once English is stated to prevail, the Thai version need not be checked. But the Thai version is often what Thai agencies and the other party actually read, and it may be relied on in practice. Another misunderstanding is that word-for-word translation makes the versions match, when different legal systems use different concepts. A good bilingual review checks the legal effect of each clause, not just linguistic accuracy.

Finally, standard foreign contracts may contain clauses that are unenforceable under Thai law, such as certain liability exclusions or overly broad non-compete clauses. Adapt them to Thai law before signing.

When amending the contract later, amend both languages together in a single amendment and have the parties sign both, so the versions do not drift apart and cause disputes over which reflects the latest agreement.

Keep the signed contract in both languages and every amendment together, with the effective date of each, so they are easy to trace back if questions arise, and tell the relevant people in your organisation after each change so everyone follows the latest version.