How and when to complete the TDAC before your trip

When the TDAC can be submitted

The official Thailand Digital Arrival Card platform accepts submissions in a window that opens a few days before arrival. The exact window is set by the Immigration Bureau and may be adjusted from time to time. As a general guideline:

• Travellers are advised to complete the form within roughly three days of their arrival date.
• Submitting earlier than the window allows is not possible; the system rejects entries that are too far in advance.
• Submitting at the very last moment is permitted in principle but increases the risk of network or technical problems.

A reasonable approach is to gather the necessary information well in advance and submit the form the day before departure or shortly after check-in for the flight.

The standard sequence of steps

The TDAC process on the official platform usually involves the following steps:

• Opening the official government website on a smartphone, tablet or computer.
• Selecting the language and starting a new arrival card.
• Entering personal details exactly as they appear in the passport.
• Entering travel information, such as flight number, arrival date and arrival airport or border checkpoint.
• Entering the address of the first accommodation in Thailand.
• Reviewing all fields and submitting the form.
• Saving or printing the confirmation page.

The confirmation typically takes the form of a reference number and may include a QR code. Travellers are advised to keep a screenshot or printed copy in case mobile data is not available on arrival.

Family members and group travel

Each traveller normally needs an individual TDAC, including children. Many travellers complete the forms in sequence using the same device. When travelling as a family, it is helpful to:

• Have every passport on hand before starting.
• Use the same arrival flight and accommodation details for consistency.
• Save each confirmation separately, labelled with the traveller's name.

Common timing mistakes

Most timing issues fall into a small number of patterns:

• Trying to submit weeks or months in advance, before the system opens the form.
• Forgetting to complete the form during a layover and arriving at immigration without it.
• Submitting a form with a draft flight number that later changes due to schedule revisions.

If flight details change after submission, the form usually allows the traveller to make a correction or submit a new entry. See the article on correcting mistakes for more detail.

Devices, connections and accessibility

The official TDAC platform is designed to work on a wide range of devices. To reduce friction, travellers can:

• Use a stable Wi-Fi connection rather than a roaming mobile signal.
• Update the browser to a recent version.
• Keep the passport scan or photograph nearby to copy numbers accurately.
• Avoid filling in the form while the device is on a very low battery.

Travellers who do not have personal access to the internet can often complete the form with help from a family member, a friend or staff at their accommodation.