Invoicing Foreign Clients From Thailand
The most common expat income pattern — and the one with the murkiest informal advice. Here's the clean structure.
First: the legality layer (before any tax talk)
| Your setup | Legal standing |
|---|---|
| Remote work for FOREIGN clients on DTV | ✅ The intended use of the visa |
| Serving THAI clients while on DTV/tourist visa | 🔴 Requires work authorization you don't have |
| Thai employer + work permit + salary | ✅ Standard employment |
"Where the client sits" is the line. Thai-source income (Thai clients, Thai projects) triggers both tax AND work-authorization requirements regardless of visa.
The invoicing mechanics
- You can't issue a Thai VAT invoice without a company — as an individual freelancer billing overseas, you simply send a plain invoice/receipt from yourself
- Payment routes ranked: Wise/fintech first, direct SWIFT for large amounts, PayPal only when clients insist (fee math here)
- Keep every invoice numbered and archived — this is your income evidence for BOTH tax systems
The tax reality (2024+ rules)
- Thai tax resident (180+ days): foreign freelance income REMITTED into Thailand is assessable at progressive rates up to 35% — with the standard 50% expense deduction available for service income (capped at 100k THB deduction)
- Money kept offshore: not assessed until remitted; spending it abroad isn't a taxable event
- US citizens: double system applies regardless — see the FEIE guide
- Some freelancers form Thai companies (Amity Treaty or standard) for rate optimization and work-permit eligibility — that's a bigger structural decision worth professional advice
Estimate your Thai liability: Tax Calculator → · Check residency status: Day Counter →
Filing mechanics for freelancers
- File P.N.D.90/91 annually (March 31 / April 8 e-file deadline) — see the filing decision guide
- Half-year P.N.D.94 filing due September 30 if you have non-salary assessable income above thresholds
- Registering for a TIN is free and takes under an hour: how to →
Educational information as of August 2026. Cross-border freelancing structures warrant personalized professional advice beyond a certain scale.