TDAC not working? Errors and fixes
Find your TDAC error or problem
| Error or situation | Official FAQ fix or guidance |
|---|---|
| Http failure response ... 429 | Refresh the page and try again. |
| Http failure response ... 0 Unknown Error | Check your internet connection. |
| QR not received by email | Contact the Immigration Officer at the entry checkpoint. |
| Website unavailable | Keep a screenshot of the error and contact airport or immigration staff. |
| A mistake in the submitted form | Check the editing rules and restricted identity fields before choosing an update or a new submission. |
| Passport-number correction | See the passport-number discrepancy notice. Submit a new TDAC if unsure. |
| Flight or hotel changed | Update the card or submit a new one before entry. |
| No email address | Create an email address, because email is how you receive the TDAC. |
| No smartphone or internet | Kiosks and Wi-Fi are provided on arrival. The FAQ lists Suvarnabhumi, Don Mueang, Phuket, Chiang Mai and Hat Yai. Kiosk QR codes are sent by email only; take a photo of the QR code from the kiosk. A printed QR document is useful if you will not have a device. |
| Cannot save progress | There is no save-and-finish-later option. Complete the form in one go; the FAQ says about 3–5 minutes per person if your information is ready. |
Editing rules and the passport-number discrepancy
How to update a submitted TDAC
Check which field needs correcting
Check the editing rules and restricted identity fields before choosing an update or a new submission.
Use Update Arrival Card
Open the official TDAC website and choose “Update Arrival Card” to correct an editable field. For flight or hotel changes, update the card or submit a new one before entry.
Submit a new form if needed
If a field cannot be updated, submit a new TDAC. Multiple submissions are allowed, and the most recent submission is valid. For passport-number uncertainty, submit a new form.
Keep the valid QR document available
Keep the QR document for the valid submission available for entry. If the QR email has not arrived, contact the Immigration Officer at the entry checkpoint.
Missing departure information
Departure Information is optional according to the official release notes. Leaving those fields blank is not itself a missing required field. Accommodation information in Thailand is still required. See how to fill out the TDAC.
Get help with the official form
Use the official website’s user guide and the email contact listed on its FAQ page, or ask airport or immigration staff on arrival. Browse the grouped TDAC FAQ for timing, group and transit questions.
People also ask
What should I do about a TDAC 429 error?
Refresh the page and try again, as instructed by the official FAQ.
Which fields cannot be edited according to the official FAQ?
Check the editing rules and restricted identity fields before choosing an update or a new submission.
Can I change my passport number after submission?
See the passport-number discrepancy notice. Submit a new TDAC if unsure.
What if I have already submitted more than one TDAC?
Multiple submissions are allowed. The system treats the most recent submission as valid.
What if my QR email never arrives?
Contact the Immigration Officer at the entry checkpoint.
Optional help with the form
The official TDAC is free, and you can complete it yourself at tdac.immigration.go.th. If you travel to Thailand often, the /tdac/ service is an optional, independent paid helper (€5 one-time) that saves your details so you don’t retype them every trip; most one-time visitors don’t need it. For that service, read tips to fill the TDAC faster and TDAC Auto-Fill help.
Sources
Official publications used for this guide.
- Thai Immigration · official TDAC FAQ
- Thai Immigration · TDAC manual and release notes
- Independent paid TDAC helper
- Helper service · tips to fill the TDAC faster
- Helper service · TDAC Auto-Fill help
The official TDAC is free at tdac.immigration.go.th. Our helper is optional and paid, and only worth it if you visit Thailand often.