If you have ever rented a condo in Bangkok, especially along the BTS Sukhumvit line around Asoke, Phrom Phong or Thonglor, you will know that lease agreements usually arrive in two languages, Thai and English side by side. Sometimes it is English only, sometimes Thai only. And that raises the obvious questions: "If the two versions do not match, which one applies?" or "Is an English lease really binding under Thai law?" Let us talk about this straight, with no beating around the bush, because a lease is something both Thais and foreigners need to understand before the pen touches the paper.

Which language does Thai law treat as the main one?

The short answer is that Thai law does not require a lease to be written in Thai only. An English lease is enforceable under the Civil and Commercial Code, because what matters is "the intention of the parties", not the language it was written in.

However, if the matter ends up in a Thai court, the court uses Thai as its official language. That means an English lease has to be translated into Thai by a certified translator, and the court will then consider that translated version. This is exactly where problems tend to appear, because translation can shift the meaning.

Say you rent a condo at The Lumpini 24 near BTS Phrom Phong, with rent of roughly 35,000-55,000 THB per month, and the lease comes in English only. That is perfectly valid. But if a dispute goes to litigation, the process becomes more troublesome because every page has to be translated.

Bilingual leases: which version carries more weight?

Many condos in expat areas such as Sukhumvit Soi 24, Soi 39 or Sathorn use bilingual contracts, meaning both Thai and English appear in the same document. This type of lease usually contains a clause saying: "In the event of any conflict between the Thai and English text, the ___ language version shall prevail."

That blank is extremely important. If it says the Thai version prevails, then Thai prevails. If it says English prevails, then English prevails. But if the clause is missing entirely, Thai courts tend to give priority to the Thai version, because it is the official language.

So before signing, whether you are renting a unit at Ideo Q Sukhumvit 36 near BTS Thonglor at 20,000-30,000 THB, or at Ashton Asoke near MRT Sukhumvit at 25,000-45,000 THB, always look closely at the clause on the "governing language" first.

Points foreigners need to watch especially carefully

For foreigners renting condos in Bangkok, a frequent problem is that the English version is written simply and briefly and looks friendly, while the Thai version contains extra details that were never translated, such as conditions for deducting from the deposit, penalties for moving out before the lease ends, or restrictions on pets.

There was a case of a foreign tenant renting a condo in the Silom area near BTS Chong Nonsi. The English version said "deposit refundable upon move-out", but the Thai version included a condition requiring 60 days' advance notice, not the 30 days everyone assumed. The result was two months of deposit money deducted.

The easy way to protect yourself is to have a Thai person you trust read the Thai version for you, or hire a lawyer to review the contract, which costs around 3,000-5,000 THB. That is certainly better value than losing the entire deposit.

Checklist before signing a condo lease

No matter which language the lease is in, the things you need to check are the same. Run through this list:

1. Lease term, usually 1 year. Anything over 3 years must be registered at the Land Department, otherwise it is only enforceable for 3 years.
2. Security deposit, normally 2 months. Are the refund conditions written clearly?
3. Common area fees, water and electricity, who pays and at what rate. Some condos charge 8-9 THB per unit for electricity, nearly double the utility authority rate.
4. Renewal, is it automatic or does it require notice, and if rent increases, is there a cap?
5. Early termination conditions, how much is the penalty and how many days of notice are needed?
6. The governing language clause, if it is a bilingual lease, which version prevails?

Which areas tend to have which type of lease?

From experience, condos in areas with lots of foreigners, such as the early stretch of Sukhumvit (Nana to Ekkamai), Sathorn, Silom and Ratchada, usually come with bilingual leases or English-only leases. Examples include Park 24 near BTS Phrom Phong at 22,000-40,000 THB, or Siamese Exclusive Ratchathewi near BTS Ratchathewi at 18,000-28,000 THB.

In areas rented mainly by Thai tenants, such as around BTS Wutthakat and Talat Phlu or MRT Lat Phrao and Huai Khwang, leases are usually Thai only, with rent of roughly 8,000-15,000 THB. At places like Lumpini Park Rama 9 or The Base Rama 9, a Thai-only lease is completely normal.

The takeaway: language matters less than understanding

Whether Thai or English, a lease is equally enforceable under Thai law. But what matters more than language is understanding the content. Read every clause, ask until every condition is clear, and if it is a bilingual lease, check which version prevails. Do not sign out of politeness towards the owner, and do not sign because an agent is rushing you. A lease protects both the tenant and the owner, so give it the time it deserves.

If you are looking for a condo to rent in Bangkok and would rather not deal with a headache of a process, try Superagent. It is a condo rental platform that uses AI to help find the unit that fits you, with no pushy agents and no need to schedule ten viewings one by one. Just tell it what you want and the system handles the rest, saving time for the things that really matter, like sitting down and reading your lease carefully before you sign.