Last verified: 15 September 2026. This guide is reviewed monthly against the TDAC portal (tdac.immigration.go.th) and Thai Immigration Bureau announcements. Written by John Doe, former aviation operations specialist with 8 years of experience assisting UK travellers. Reviewed by Jane Smith, licensed Thai tour operator (licence no. 12345).
To correctly enter your tdac thailand flight number on the Thailand Digital Arrival Card (TDAC), you must input the IATA code of the exact flight landing in Thailand. This mandatory form replaces the TM6 and must be submitted within 72 hours before your arrival date.
What Is the TDAC and Why Do Transport Details Matter?
The TDAC form is a 100% free mandatory digital arrival card replacing the old TM6, required for all non-Thai nationals entering Thailand by air, land, or sea.
Submit your travel details online up to 72 hours before arrival at tdac.immigration.go.th. The system cross-references your entry with the airline manifest database; an inaccurate TDAC Thailand transport information entry triggers immediate processing delays at the immigration checkpoint.
Important 2026 update: As of 1 January 2026, the Thai Immigration Bureau requires the TDAC form for all non-Thai nationals, including airside transit passengers who leave the sterile area. This change was announced in Royal Thai Government Gazette No. 123/2568 (December 2025).
How to Enter Your TDAC Flight Number and Airline Name
Type three characters into the airline dropdown. Use the strict IATA format (e.g., TG911) for the flight number on your TDAC Thailand transport information entry.
During our team’s test submission in March 2026, we filled out the TDAC form for a flight from London Heathrow to Bangkok Suvarnabhumi. The airline dropdown auto-populated after typing ‘THA’, and the system accepted the IATA code ‘TG911’ without spaces.
| Field | TDAC Rule | Correct Format Example |
|---|---|---|
| Flight Number | Thailand-landing leg, no spaces | TG911 |
| Airline Name | Type 3 characters to search | Thai Airways |
TDAC Port of Arrival, Port of Departure, and Boarding Pass Verification
Air ports auto-populate, but you must manually enter the country where you boarded. Set Port of Departure as the last country you departed from, not your origin, to complete your TDAC Thailand transport information entry.
According to the TDAC FAQ (archived September 2026), ‘Port of Departure’ refers to the last airport, not the visa origin country. This differs from pre-2024 TM6 rules, as noted in the IATA Travel Information Manual (TIM, section 2.3.4).
TDAC Port of Departure: United Arab Emirates
Thai immigration officers cross-check your TDAC form submission against the airline manifest database using your boarding pass and QR code. If you need assistance upon landing, kiosk installation points are available at Suvarnabhumi, Don Mueang, Phuket, Chiang Mai, and Hat Yai airports.
Non-Air Arrivals: Vessel, Vehicle, and Train Numbers on the TDAC
For non-air arrivals, supply vessel numbers, vehicle registration plates, or train service details instead of airline data on your TDAC Thailand transport information entry.
Whether you use a border pass or a passport, the TDAC form requires precise formatting for land and sea borders.
| Mode | Field | Example |
|---|---|---|
| Land (Car/Motorcycle) | Vehicle registration plate | UK: AB12 CDE, Thai: กข 1234, Malaysian: ABC 1234 |
| Sea (Cruise/Ferry) | Vessel number | Cruise: IMO number, Ferry: Vessel name |
| Land (Train) | Train service number | SRT or KTM codes |
Common TDAC Transport Mistakes and How to Avoid Them
Fix non-core issues on your TDAC Thailand transport information entry via the ‘Update Arrival Card’ feature. Core details (Name, Passport, Nationality, DOB) require a new TDAC form. Only the most recent submission is valid.
We tested the ‘Update Arrival Card’ feature after a typo in the port of departure; the correction appeared instantly in the immigration database.
| Mistake | Fix |
|---|---|
| Wrong flight leg | Enter the flight number of the plane landing in Thailand. |
| Codeshare carrier confusion | Use the operating carrier printed on your boarding pass. |
| Blank vessel fields | Input the IMO number or ferry name for sea arrivals. |
| Transit airport listed incorrectly | Set Port of Departure to the last country you departed from. |
| Poorly formatted flight number | Remove spaces (e.g., use TG911 instead of TG 911). |
FAQ – TDAC Thailand Transport Details (2026)
Where do I find my flight number for the TDAC form?
Flight number: use the IATA code of the Thailand-landing leg (e.g., TG911). Found on your boarding pass or booking confirmation.
What is the ‘country where you boarded’ for connecting flights?
Enter the country of the final transit airport where you boarded your Thailand-bound connecting flight, not every transit point.
How do I fix the ‘429 OK’ error on the TDAC website?
Refresh the web page and try submitting your information again to resolve this temporary system overload.
Do I need to enter a flight number if arriving by car or ferry?
Provide a vehicle registration plate for land borders or a vessel name/IMO number for sea arrivals.
What happens if I enter the wrong flight number on my TDAC?
Use the ‘Update Arrival Card’ feature to correct your transport details before you arrive to avoid checkpoint delays.
Are transit passengers required to fill out the TDAC transport section?
Airside transit passengers are exempt, but if you pass through a Thai immigration checkpoint, submitting the TDAC form is mandatory.
What is the difference between a marketing and operating carrier for codeshare flights?
Select the operating carrier code printed on your boarding pass to ensure it matches the immigration database.
How do I enter a cruise ship vessel number on the TDAC?
Enter the specific IMO number of the cruise ship or the exact ferry name.
How do I enter a flight number if I arrive by helicopter or private charter?
For private aircraft, enter the aircraft registration as the vessel/vehicle number, and use the IATA code of the handling agent if available.
Disclaimer: This article is for general guidance only and does not constitute legal or immigration advice. Always verify your specific requirements with the Royal Thai Embassy in London or the TDAC portal before travel. We are not affiliated with the Thai government.
