Thailand has replaced the paper TM6 form with the Thailand Digital Arrival Card (TDAC). This online pre-arrival system makes the entry process faster and more efficient.
By submitting your details before you travel, you receive a unique QR code that immigration officers scan when you arrive. In this complete guide, we’ll cover what TDAC is, who must submit it, when and how to apply, what information you’ll need, common errors and solutions, and what happens once you land in Thailand.

Who must submit? In practice, almost every foreign traveller entering Thailand must complete TDAC, regardless of whether they arrive by plane, land crossing, or sea.
Children also require their own TDAC submission, usually filled in by a parent or guardian. Even holders of diplomatic or official passports are expected to comply unless specifically exempted. Airline and ship crew may also need to complete the form, depending on airline regulations.

When and how often? TDAC should be submitted within the days leading up to your trip, ideally 24 hours before departure. Each submission is tied to a specific journey, so you’ll need a new TDAC each time you enter Thailand. If your flight changes, simply complete a new submission — the most recent QR code will always be the one that counts at immigration.

What information is required? To complete TDAC you’ll need your full name, passport details, nationality, flight number and date, your first accommodation address in Thailand, and contact information. Submissions for multiple family members can be done in one session, but each traveller will still receive their own QR code.

Transit and special cases. Passengers on technical stops or pure transit flights that remain airside generally do not need TDAC.
However, the moment you pass through immigration — even for a short layover — you must have a valid TDAC. Travellers arriving by land or sea are expected to complete the form as well.
Those using a visa-on-arrival can still rely on TDAC for faster processing, as the two processes are separate.

Submission channels. The TDAC form is primarily online. For travellers without smartphone access, kiosks at major Thai airports like Suvarnabhumi and Phuket
allow submission and QR printing. These kiosks can also reprint your QR if you didn’t receive it by email. Remember to check your spam folder, as many travellers find the confirmation there.

Common errors. Sometimes submissions trigger technical issues. A message reading
“Http failure response … 429 OK” usually means the system is overloaded. Waiting a few minutes and trying again usually solves it.
An error such as “0 Unknown Error” is often linked to cached data or network problems; clear your browser cache, disable VPNs or ad blockers, try Incognito mode, or switch devices and connections before retrying.

Security and data protection. The TDAC system uses encryption and is managed by Thai authorities. Data is stored for immigration purposes and is not shared with other countries unless required under official agreements. Submitting early not only avoids stress but also keeps your information aligned with your travel record before arrival.

At immigration. Once you land, present your QR code to the officer. They’ll scan it to retrieve your pre-submitted data.
Expect routine questions about your accommodation, purpose of visit, and return ticket, just as before. The difference is that with TDAC, your core details are already in the system, saving time and reducing paperwork.

Key takeaway. TDAC is mandatory for most foreign travellers, simple to complete, and vital for a smooth arrival. Submit it once per trip,
use the latest QR, and carry it ready to show. If errors occur, retry calmly or use an airport kiosk. By preparing in advance, you ensure your time in Thailand begins not with long queues, but with more time to explore temples, beaches, and street food.