The Airside vs. Landside Rule: When the Thailand Digital Arrival Card is Mandatory
Planning a multi-leg journey often includes a stop in Thailand, home to the major international hubs of Suvarnabhumi (BKK) and Don Mueang (DMK). If you are transiting through these airports, the question of whether you need to complete the mandatory Thailand Digital Arrival Card (TDAC Arrival Card) is critical.
The answer is simple, but often misunderstood: It depends entirely on whether you pass through Thai Immigration.
Trevalo clarifies the difference between a direct transit and a self-transfer, ensuring you know exactly when the TDAC Arrival Card is required for your layover in Bangkok.
🔑 Section 1: The Core Rule — Immigration Clearance
The TDAC is a declaration for entry into Thailand. If you never formally enter the country by passing through the passport control gates, the TDAC is not required.
1. TDAC Arrival Card IS NOT Required: Direct Airside Transit
A TDAC is NOT required if you meet all of the following criteria:
- Single Ticket: Your journey is booked on a single, through-ticket to your final destination (e.g., London to Sydney via Bangkok).
- Airside Stay: You remain entirely in the international transit or departure area of the airport (the “airside”).
- No Immigration: You do not pass through the Thai Immigration checkpoint.
- Checked Luggage: Your luggage is checked through to your final destination, and you do not need to retrieve and re-check it in Bangkok.
Scenario: You land at BKK, follow the “Transfer/Connecting Flights” signs, and proceed directly to your next departure gate without ever seeing an Immigration Officer. No TDAC is needed.
2. TDAC Arrival Card IS Mandatory: Landside Entry (Self-Transfer)
A TDAC IS MANDATORY if your layover requires you to do any of the following:
- Change Airports: You transfer between Bangkok’s two airports (e.g., DMK to BKK). This requires you to physically exit the airport and travel across the city.
- Retrieve Luggage: You must pass through Immigration and Customs to collect and re-check your luggage (a common requirement for budget airlines or separate tickets).
- Self-Transfer: You have two separate, non-linked tickets (e.g., booking with two different airlines) and must check in at the departure desk for your onward flight.
- Long Layover: You choose to leave the airport (e.g., to visit Bangkok for a few hours or stay in an airport hotel outside the terminal).
Scenario: You land at BKK and need to collect your bags to check in for your next flight. You must present your passport and TDAC at the Immigration counter to collect your entry stamp. TDAC is needed.
🛑 Section 2: Scenarios That Always Require a TDAC Arrival Card
1. Self-Transfer & Separate Tickets
This is the most common reason travelers need the TDAC Arrival Card during a layover. When you book two separate tickets (e.g., one to Bangkok, one from Bangkok), the airline will typically not check your baggage all the way through.
- Process: To retrieve your bags and proceed to the departure area for your next flight, you must officially enter Thailand via the Immigration checkpoint.
- Requirement: TDAC is mandatory, regardless of how short your time on the “landside” is.
2. Changing Airports (BKK – DMK)
If your connecting flight departs from the other airport (BKK or DMK), you must leave the transit area. Consequently, you are officially entering Thailand to complete the transfer.
- Requirement: You must complete the TDAC Arrival Card and pass through Immigration. You should list your first night’s accommodation as “Bangkok Airport” or the name of the airport hotel if you are staying near the airport.
3. Transit Visa Exemption
Some nationalities require a Transit Visa even for airside transfer. While the TDAC is not a visa, the requirement to complete the TDAC generally aligns with the requirement to have a valid entry document (visa or visa-exempt stamp). If your journey requires you to enter Thailand (pass Immigration), you need both a valid means of entry and the TDAC.
💡 Section 3: Layover TDAC Arrival Card Submission Tips
If you determine that your layover requires you to submit the TDAC Arrival Card, use these tips for a smooth process:
| Tip | Detail |
| Address in Thailand | If you are only leaving the airport for a few hours, enter “Suvarnabhumi Airport” or “Don Mueang Airport” in the accommodation field. If you are staying at an airport hotel outside the terminal, use that hotel’s address. |
| Submission Timing | The TDAC 3-Day Rule still applies. Submit the form no earlier than 72 hours before your arrival time in Bangkok (GMT+7). |
| Family/Group Submission | If traveling with family, use the TDAC system’s “Group” application feature to submit all required forms under one registration, making on-site validation faster. |
| Losing the QR Code | If you lose your TDAC Arrival Card confirmation, you can easily retrieve it using the “Update Arrival Card“ function on the official TDAC portal before you travel. |