Best Law Firms for Tax Residency in Thailand: 6 Options in Bangkok

Quick answer

Law firms in Bangkok that advise foreigners on Thai tax residency include Herrera & Partners, Tilleke & Gibbins and Luther. They range from a Bangkok corporate and litigation firm with clients from 80+ countries to a regional firm ranked by Chambers for tax and a German firm with a Bangkok office since 2018. Since 1 January 2024, Thai tax residents pay tax on foreign income they bring into Thailand, so the timing of your stays and your transfers now decides what you owe.

What is tax residency in Thailand?

Under Section 41 of the Thai Revenue Code, you’re a Thai tax resident if you stay in Thailand for 180 days or more in a calendar year, in one stay or several. Nationality and visa type don’t change this test.

Residence decides how your income is taxed:

Thai-source income is taxable for everyone, resident or not.
Foreign-source income is taxable for residents when it’s brought into Thailand. Under Revenue Department notifications Por. 161/2566 and Por. 162/2566, this applies to income earned from 1 January 2024 onwards, whenever it’s remitted.
Savings from before 2024 can be brought in tax-free, so records of what you held before that date matter.

Residents pay progressive personal income tax. The first THB 150,000 of net income is exempt, and rates rise from 5% to 35%, with the top rate applying above THB 5 million.

Two other rules shape the bill:

Double tax agreements. Thailand has signed 61 double tax agreements, including with the United States, the UK, France and Germany. Tax paid in a treaty country can usually be credited against Thai tax.
LTR visa exemption. Under Royal Decree 743, the Wealthy Global Citizen, Wealthy Pensioner and Work-from-Thailand Professional categories of the Long-Term Resident visa are exempt from tax on foreign income.

A draft rule to exempt foreign income remitted in the year it’s earned or the following year hasn’t been published in the Royal Gazette, so it isn’t law yet.

How to manage your Thai tax position

Most foreign residents work through 5 steps:

Count your days. Track days in Thailand per calendar year against the 180-day threshold, since residence is set year by year.
Map your income. Separate Thai-source income, foreign income earned before 2024 and foreign income earned from 2024, and check which of them you’ll bring into Thailand.
Check treaty relief. Review the double tax agreement between Thailand and the country where the income is taxed, and keep proof of foreign tax paid.
Register and file. Obtain a Thai tax ID and file a personal income tax return by 31 March for paper filing, or by early April online, for the previous year.
Prove your residence abroad. Request a Thai tax residency certificate when your home country needs proof. Thailand isn’t part of the apostille system, so documents for use abroad are legalised through the Ministry of Foreign Affairs and the relevant embassy, which can take over a month.

6 law firms that advise on tax residency in Bangkok

All 6 firms below have a Bangkok office and advise foreign individuals on Thai tax residency.

1. Herrera & Partners (H&P)

Herrera & Partners is a Bangkok firm specialising in corporate, commercial law and litigation, with clients from more than 80 countries. Its tax residency team prepares legal opinions on tax residency and tax exposure, covering residence, business activities, source of income and double tax agreement analysis.

Strengths

Handles the full individual cycle: Thai tax ID, annual personal income tax filing, an English-language tax residency certificate, and representation before the Revenue Department.
Legalises tax opinions and certificates through the Ministry of Foreign Affairs and the client’s home consulate, and obtains LTR visas for clients who qualify for the foreign income exemption.

Limitations

Works from a single Bangkok office, so clients outside the capital are served remotely.
Working languages are Thai, English and Spanish.

Best fit for: high-net-worth individuals, retirees and LTR applicants who need a legal opinion on their Thai tax exposure that their home tax authority will accept.

2. Tilleke & Gibbins

Tilleke & Gibbins was established in Bangkok in 1890 and is the largest independent law firm in Thailand, with more than 250 lawyers and consultants across 6 Southeast Asian countries. Its tax team is ranked Band 3 for Tax in Thailand in the Chambers Asia-Pacific 2026 guide.

Strengths

Its tax lawyers have analysed the Revenue Department’s orders on foreign-sourced income, including the rule that closed the remittance loophole from 2024 and the exemption for income earned before that date.
Covers tax planning, transfer pricing and tax disputes, which helps when an individual’s tax position is tied to a company.

Limitations

The tax practice is built around corporate clients, in energy, logistics, manufacturing and technology.
Personal tax work sits inside a full-service regional firm, which suits complex cases more than a single annual return.

Best fit for: executives and business owners whose personal tax position depends on their company, shares or cross-border income.

3. Luther

Luther is a German law firm with 420 lawyers and tax advisors, and its Bangkok office opened in 2018. The Bangkok team combines international professionals, Thai lawyers, accountants and tax advisors, and its tax work covers inbound and outbound international tax, direct taxes and double tax agreements.

Strengths

Handles payroll for companies, including income tax and social security filings for employees, which covers foreign staff on Thai payrolls.
Runs visa, work permit and permanent residency applications, and works across 8 Asian offices, including Singapore, Shanghai, Kuala Lumpur and Jakarta.

Limitations

The practice focuses on companies and their employees, so private clients without a business connection are a smaller part of its work.
Personal income tax isn’t offered as a standalone service; it runs through tax compliance and payroll.

Best fit for: German and European companies posting staff to Thailand, and executives whose tax residency is handled through their employer.

4. Lex Bangkok

Lex Bangkok is a Bangkok law firm serving international businesses and individuals, with a headquarters in Bueng Kum and a Sukhumvit branch. Its team works in English, Thai and Japanese, and advises expats, retirees and foreign investors on residency, remittance planning, double tax treaty relief and annual filing.

Strengths

Advises on when foreign income becomes assessable, which is the year it’s remitted to Thailand for a tax resident.
Combines personal tax advice for residents with company registration, BOI work, accounting and work permits for clients who also run a business in Thailand.

Limitations

A small team led by managing partner Ryutaro Sato, with 4 named lawyers and counsel.
Tax advice is one item in a wide service list that also covers licensing, IP, translation and notary work.

Best fit for: Japanese and other foreign residents who want remittance planning and treaty relief alongside business set-up.

5. Br’er Rabbit Legal

Br’er Rabbit Legal is a Bangkok firm in 66 Tower on Sukhumvit Road, Bang Na. It advises foreign tax residents and business owners on remittance planning, LTR visa structuring and Thai tax compliance, and its services also cover company formation, licensing and citizenship by investment.

Strengths

Tracks the remittance rules closely, including the status of the draft exemption for income remitted in the year earned or the following year, which isn’t law yet.
Structures LTR visa applications around the Royal Decree 743 exemption for foreign income, and documents pre-2024 savings so they can be remitted tax-free.

Limitations

The main working language is English, with a dedicated Chinese enquiries service.
The office is in Bang Na, in eastern Bangkok, away from the central business districts, though clients can reach the team by WhatsApp.

Best fit for: foreign residents and Chinese-speaking clients who want remittance planning built around an LTR visa.

6. Benoit & Partners

Benoit & Partners is a Bangkok firm founded by 2 Thai partners and Monaco-born managing partner Laurent Benoit, with a team of 35 people, including 15+ Thai-licensed lawyers and 10+ accountants. Its tax and relocation department advises on tax residency, double tax treaties and foreign income remitted to Thailand.

Strengths

Filed more than 300 tax returns in 2025 and handles TIN registration, relocation tax planning, audits and reassessments.
Pairs tax work with visas and work permits, having obtained more than 800, and has supported more than 1,000 relocations.

Limitations

Working languages are English, Thai and French, plus Italian at partner level, with partner firms in France and Italy.
The firm covers corporate, real estate, accounting and litigation work as well, so tax residency is one department of six.

Best fit for: French- and English-speaking expats relocating to Thailand who want tax, visa and accounting work under one roof.

Recap table

Firm	Size	Office	Working languages	Tax residency work	Best fit for
Herrera & Partners	Corporate and litigation firm, clients from 80+ countries	Bangkok	Thai, English, Spanish	Legal opinions, tax ID, filing, residency certificate, legalisation, LTR	High-net-worth individuals and retirees
Tilleke & Gibbins	250+ lawyers and consultants; Chambers Band 3 for Tax	Bangkok, plus 5 other countries	Thai, English; China and Japan desks	Foreign-sourced income analysis, tax planning, disputes	Executives and business owners
Luther	420 lawyers and tax advisors; Bangkok since 2018	Bangkok, plus 7 Asian offices	English, Thai	International tax, DTAs, payroll income tax	Staff posted by European companies
Lex Bangkok	Small firm	Bangkok (Bueng Kum, Sukhumvit)	English, Thai, Japanese	Residency, remittance planning, treaty relief, filing	Japanese and foreign residents with a business
Br’er Rabbit Legal	Small firm	Bangkok (Bang Na)	English, Chinese	Remittance planning, LTR structuring, compliance	LTR applicants
Benoit & Partners	35 people, 10+ accountants	Bangkok, plus Phuket, Pattaya, Koh Samui, Koh Phangan	English, Thai, French	300+ returns filed in 2025, relocation tax planning, audits	Relocating expats

How to choose a lawyer for Thai tax residency

What to check before hiring

Residence analysis. Ask how the lawyer would assess your residence across Thailand and your home country, including the tie-breaker rules in the relevant tax treaty.
Remittance planning. Ask how the firm separates pre-2024 savings from later income, and what records you need to prove the difference.
Treaty relief. Ask the lawyer to check the treaty between Thailand and your income country, and how foreign tax credits will be claimed.
LTR eligibility. If you have significant foreign income, ask whether you qualify for an LTR category that exempts it.
Filing and follow-up. Check whether the firm files the return, obtains the residency certificate and handles questions from the Revenue Department.

Warning signs

Advice that relies on the draft exemption. The proposal to exempt income remitted within a year isn’t law, so planning that assumes it may leave you exposed.
Days-only advice. The 180-day test sets residence, but what you owe depends on income source, timing of remittances and treaty relief too.

FAQ

How many days make you a tax resident in Thailand?

180 days or more in a calendar year, counted across one stay or several. Your nationality and visa type don’t affect the test.

Is foreign income taxed in Thailand?

For tax residents, foreign income earned from 1 January 2024 is taxable when it’s brought into Thailand, in the year of remittance. Income earned before 2024 can be brought in tax-free.

Does the LTR visa exempt foreign income from Thai tax?

Yes, for 3 categories: Wealthy Global Citizen, Wealthy Pensioner and Work-from-Thailand Professional. Royal Decree 743 exempts their foreign income from Thai personal income tax.

What are the personal income tax rates in Thailand?

Rates are progressive. The first THB 150,000 of net income is exempt, then rates run from 5% to 35%, with 35% applying to net income above THB 5 million.

How do I prove Thai tax residency to my home country?

Request a tax residency certificate from the Revenue Department. Thailand isn’t part of the apostille system, so the certificate is legalised through the Ministry of Foreign Affairs and your embassy, which can take more than a month.