July 2026 update: For marriage visa extensions, Chiang Mai immigration now has some additional requirements that are not mentioned online. In the age of AI, there are now more paper forms to fill out. However, some of the online PDF forms to print out now allow you to fill your information by typing directly into the PDF. Make sure to download those from official Thai immigration websites rather than third-party websites, such as websites belonging to visa services and universities. Each year, the immigration officer will give oral instructions on how to better prepare your documents for next year, because document preparation varies from year to year as new bosses and officers come in and out. As usual, it's still a good idea to have a 1970s-style mini-printing press in your house so that you won't have to make multiple trips to print shops: a sturdy photocopy machine (I use a Brother DCP-1510, which is perfect for preparing documents for Thai bureaucracy), along with 2-3 toner cartridges, a 500-sheet pack of A4 paper (70 gsm would be enough, no need for the heavier 80 gsm types), several pens with blue ink, binder clips, paper clips, expanding folders, and a gluestick. 1. STM forms Chiang Mai immigration now requires 3 different STM forms for the marriage visa extension. 1a. STM-2 - Chiang Mai immigration told me that I need to sign two language versions of the STM-2 form, one completely in English and one completely in Thai (the form is printed in Thai, but you can still write everything out in English). None of these can be found online. Make sure to fill in identical information. 1b. STM-9 - Fill out and sign. This is an acknowledgement of overstay penalties. 1c. STM-11 - Fill in both the top half (printed in Thai, but can be filled out in English) and bottom half (printed in English). - Application for extension of temporary stay in the Kingdom: In the English-language section, write "1" year. In the Thai-language section, for ปีที่___ (pii thii ___ ) write which year you're on your marriage extension (your 5th year on your marriage visa, 10th year on your marriage visa, etc.). - Reason: Support Thai wife / Support Thai family - Name of company/partnership: your current address - Coordinator name: your wife's name - Position: (leave blank - do not fill out) 2. Couple photographs Photographs: The immigration officer says that she now prefers 2 color photos on the front side and 2 color photos on the back side. A few years ago she said that she preferred to have 4 color photos on the same page (front side only), but that has now changed. Make sure to leave some space in the middle (space between the photographs) for the immigration officer to put their stamps and signatures. There is no need to take bedroom photographs anymore, since Thai wives were complaining about it to immigration. Now you can take photos in the living room and dining room. A photograph of you and your wife in front of your house number is still required. The immigration officer will likely also briefly ask a few questions, such as what your wife does for a living. There will be very few questions for people doing their 3rd or 4th annual extension, or beyond. 3. Bank documents 3a. Bankbook update - Make sure to have them put your bankbook into a machine that stamps and updates the list of your transactions. Have them photocopy the updated pages twice (this should be free). 3b. Bank statement - Do not ask for more than 6 months statement, since this will several days for the bank to process, at least for Bangkok Bank (in this case, you will be told to come back again to get your statement after a few days or next week). 3 months would be enough, although I chose to go for 6 months. 3c. Bank letter/certificate: Together, 2 copies of the bank letter (nangseu rap rong หนังสือรับรอง) , and 2 copies of the bank statement should cost 400 baht, at least for Bangkok Bank. 4. Process for coming back on the next day If you do your document check in the afternoon after the 12-1 pm lunch break (every single part of immigration closes at 12:00 pm sharp, even the print shop), you might be told to come back tomorrow morning if there are no queue numbers left. I came at 1 pm, had to fill in additional STM forms that I never had to fill out before, and was told to come back the next day. The document check officer recommended me to arrive at 7:30 am to put one set of my prepared documents in a basket by the window next in front of Counter C. The other duplicate set of prepared documents should remain with me. It's first come first serve - the documents at the bottom of the basket get the first queue numbers. Hence, there is no need to get a queue number at the front area that used to be the COVID-19 screening area. Queue numbers are given out by the document check officer at 8:30 am when the document check center officially opens up. I came at 7:50 am and had to wait until around 10:30 am. Everything was done at 11:30 am. This year in 2026, it is noticeably much more crowded than in 2020-2025. Most applicants are from China and Myanmar, with some South Koreans, a smattering of citizens from various neighboring Asian countries, and some Westerners. There are noticeably fewer Westerners now than before (a few years ago). 5. TDAC Thailand now uses the TDAC (Thailand Digital Arrival Card) form instead of TM-6 (the arrival card that they used to pass out on flights to Thailand). You should fill out your most recent TDAC number in your TM-7 form (the main application form with your color photo that goes at the beginning of your marriage extension document stack). However, you do not need to print out and sign your TDAC (Thailand Digital Arrival Card) PDF acknowledgement receipt from your email. 6. Country names The immigration officer said that applicants should write out the complete names of their home countries - "United States" instead of "US" or "USA", "United Kingdom" instead of "UK", and so on. 7. Signatures on photocopies Your signatures on your photocopies should not be at the very bottom. Make sure to leave some space below your signature for the immigration officer to sign and stamp. 8. Bank balances The immigration officer says that it's best to deposit several thousand baht more in addition to the 400k/800k baht minimum that is required, just in case banks unexpectedly charge maintenance fees. 9. Order of documents The TM-7 (main application form) goes first. The back side of the TM-7 with your color photo should actually be placed in front, so that immigration officers can immediately recognize which set of documents they are dealing with just by looking at your photo. Your passport photocopies come next. Afterwards, in order: your two marriage certificates (KR-3 and KR-2), photocopies of your wife's ID card and household registration, STM forms, handdrawn map to your house, and photos of you and your wife. The document check officer will help you sort out the document order, but it's best to get everything in order first so that the document check process takes less time. Use a binder clip, not a paper clip, since you will be dealing with large stacks of documents. Have at least 3-4 binder clips just in case, since those can get easily lost. It's helpful to have 1-2 pens in your pocket so that immigration wouldn't have to go looking for spare pens for you. 10. Parking The 20-baht parking lot across the street from the immigration office has now changed its entrance. It's just before the red pedestrian crossing, so make sure to look out for that as you make a U-turn from the airport entrance intersection. You also can take a break at the Cafe Amazon, 7-Eleven, and bami noodle restaurant across the street from the immigration office if needed. Hope this helps!
