Common mistakes and problems with the TDAC

Mismatches between the form and the passport

The single most common source of issues is a difference between the data entered on the TDAC and the data printed in the passport. Examples include:

• Reversing first names and family names.
• Leaving out a middle name that is shown in the passport.
• Typing the passport number with extra spaces or confusing similar characters (such as the number zero and the letter O).
• Entering the wrong nationality when a traveller has dual citizenship.

Officers compare the form to the passport, so even small discrepancies can lead to questions. Copying directly from the machine-readable zone reduces this risk.

Wrong arrival date or flight details

Another frequent issue is incorrect travel information. This often happens when:

• The traveller confuses the local departure date with the arrival date in Thailand (which may fall on the next calendar day due to time zones).
• A flight number changes due to a schedule revision and the form is not updated.
• A connecting flight is used instead of the final inbound flight to Thailand.

The TDAC should refer to the flight or transport that actually crosses the Thai border, not earlier legs of the journey.

Incomplete or generic accommodation details

The form expects a real address for the first night in Thailand. Entries such as 'hotel in Bangkok' or simply a city name without further detail are likely to be rejected or cause additional questions. Travellers should:

• Use the exact property name from the booking confirmation.
• Include the street, district and province where available.
• Avoid leaving fields blank simply because the booking is not finalised.

If the trip involves several places, the address of the first night is normally what the form requests.

Submitting too early or too late

Some travellers try to submit the form weeks before departure and discover that the system does not yet accept their dates. Others delay submission until they arrive in Thailand and run into network problems. A balanced approach is to submit the form a day or two before departure, once travel plans are confirmed.

Technical issues

Although the platform is broadly stable, occasional issues do occur. Typical reports include:

• The page failing to load due to a slow or interrupted connection.
• Session time-outs when the form is left open without activity.
• Confirmation emails arriving in spam folders.

In most cases, refreshing the page, using a different browser or trying again later resolves the problem. Repeated, persistent issues can be reported through the official support channels listed on the government website.

Misunderstanding the role of the TDAC

Finally, some travellers expect the TDAC to function as a visa or an entry permit. It does not. The form is a declaration; the actual decision to admit a traveller is made by the immigration officer at the border. A correctly submitted TDAC is one step in the process, not a guarantee.