The quick answer
For a printed Thai letter or bill, a clear photo run through a camera translator (Google Translate or Google Lens) gives you a rough English version in seconds. That is often enough to spot the sender and an amount. It is not enough when the document has a deadline, a fine, a contract clause or anything you need to act on. For those you want an explanation, not just a translation. For anything you must submit to an embassy, court or government office, you need a certified translation.
Your options, compared
| Option | Good for | Watch out for |
|---|---|---|
| Camera translation (Google Translate, Google Lens) | Free, instant gist of printed text, signs and short notices | Breaks up tables and forms, struggles with handwriting, translates words without explaining Thai processes (what a TM30 is, what “ค้างชำระ” means for you) |
| General AI chat apps | Longer documents, follow-up questions | Can sound confident when it has misread the photo. Check amounts and dates against the original Thai |
| A Thai friend or your landlord | Context and local know-how | Favours run out, and the person explaining a lease may be the person who wrote it |
| Certified translator | Documents you must submit officially | Costs money and takes days. It translates, but doesn’t advise you what to do |
| Kao Jai | Everyday paperwork: what it is, what you owe, by when, next step, with red flags on leases and a reply drafted in polite Thai | An explanation, not legal advice or a certified translation |
How to take a photo that translates well
- Flatten the page and shoot straight on, not at an angle.
- Use daylight or a bright room, with no shadow from your phone across the text.
- Get the whole page, including the header (who it’s from) and the bottom (dates, amounts, signatures).
- One photo per page for multi-page leases, in order. A PDF is even better if you have one.
- Check the numbers yourself. Amounts, dates and reference numbers are the things that matter most and the easiest for any tool to misread.
Dates: the Buddhist year catches everyone
Thai documents usually use the Buddhist Era (พ.ศ.), which is 543 years ahead of the Western calendar. So 2569 is 2026, and a due date written “15 ต.ค. 69” means 15 October 2026. Months are often abbreviated: ม.ค. (January), ก.พ. (February), มี.ค. (March), เม.ย. (April), พ.ค. (May), มิ.ย. (June), ก.ค. (July), ส.ค. (August), ก.ย. (September), ต.ค. (October), พ.ย. (November) and ธ.ค. (December).
When you need a certified translation
If a document has to be submitted (for a visa, a marriage registration, a court case or a foreign authority), the receiving office decides what it accepts. That is usually a translation by a professional translator, and sometimes one that is also certified by Thailand’s Ministry of Foreign Affairs, Department of Consular Affairs. Ask the receiving office first. An app explanation, including Kao Jai’s, is for your understanding only.
Documents expats most often need help with
- Leases and rental contracts: see Thai lease red flags
- Electricity and water bills: see Thai electricity bills explained
- Immigration paperwork: see TM30 and the 90-day report
- Condo juristic office notices, school letters, bank letters, traffic fines and land tax bills: see the Thai documents glossary