Tax documents and Double Tax Agreement (DTA) claims
Claiming DTA relief usually requires a Certificate of Residence (R.O.22) from the Thai Revenue Department together with consistent income evidence, and the translation often has to be certified before use abroad.
Documents to prepare
- Certificate of Residence (R.O.22)
- Withholding tax certificate (R.O.21) where tax paid must be evidenced
- Filed returns: PND.90/91 for individuals or PND.50 for companies
- Passport / ID and evidence of days present in Thailand
- Contracts or documents showing the source of income
Step-by-step procedure
1. Confirm residence status
Verify that the day-count threshold is met for the tax year claimed.
2. Apply for R.O.22
File the application with the Revenue Department together with income and filing evidence.
3. Align the supporting set
Figures in the returns, contracts and payment evidence must match.
4. Translate and certify
Where the destination requires another language, certify the translation at the Department of Consular Affairs.
5. Final legalization
Apostille or destination embassy, per the receiving tax authority's rules.
Pitfalls to avoid
- The tax year on the R.O.22 must match the year claimed, or the whole file is refused.
- Mismatches between filed figures and payment evidence trigger requests for more documents.
- Some countries require their own form signed by the Thai Revenue Department, not only the R.O.22.
Advisory tips
- Ask the receiving tax authority first whether it wants the R.O.22 or its own country form.
- Allow for Revenue Department processing queues, especially early in the tax year.
- Keep certified copies for the following year to avoid repeating the work.
Let us handle it end to end
Prefer not to handle the queues yourself, or worried about a rejection? Send us photos of your documents for a free pre-check. We handle the full chain — obtaining certified copies, translation, certification and submission — and keep you updated at each step. Reach us on LINE, phone or email during business hours.
Let us handle it end to end