Under Thai contract law the parties to the contract must both have the same understanding of the terms of the agreement. This is essential for the contract to be valid. The wording in both languages must be confirm the intentions of the parties. A common phrase in a contract between a foreigner and a Thai is that for example the English language shall govern the contract, but when the there is significant difference between the Thai and English language it is in court not always certain how a judge will interpreted the contract, even though the civil and commercial code in section 14 specifies:
In English
Whenever a document is executed in two versions, one in the Thai language , the other in another language, and there are discrepancies between the two versions, and it cannot be ascertained which version was intended to govern, the document executed in the Thai language shall govern.
In Thai:
มาตรา 14 ในกรณีที่เอกสารทำขึ้นไว้หลายภาษาไม่ว่าจะเป็นฉบับเดียวกันหรือหลายฉบับก็ตามโดยมีภาษาไทยด้วย ถ้าข้อความ ในหลายภาษานั้นแตกต่างกัน และมิอาจหยั่งทราบเจตนาของคู่กรณี ได้ว่าจะใช้ภาษาใดบังคับให้ถือตามภาษาไทย
It should also be noted, for a contract to be executed or a transaction completed, government departments in Thailand require a separate agreement to be signed in Thai script only, often in a certain format. They only accept Thai language. Be sure both parties have the same intentions when a contract is in dual language and languages expressions in the contract are conform their intentions and understanding.