Working in Thailand as an Expat 2026: Non-B Visa, Work Permit, 90-Day Reporting, Personal Income Tax and Social Security Explained

Key takeaways

• You need both a Non-Immigrant B visa and a work permit. One without the other is not enough, and arriving visa-free or on a tourist visa to "start work while the paperwork catches up" is illegal.
• The company must qualify before you do. An ordinary Thai company needs four Thai employees enrolled in social security and THB 2 million of paid-up capital for each foreign employee; BOI-promoted companies are exempt from both.
• Since 13 October 2025 work permit applications are filed online through the Department of Employment's e-Work Permit system, with paper filing only where the system fails.
• Your salary must clear Immigration's nationality-based benchmark when the one-year extension is applied for; for US, Canadian, Japanese, Australian and most European nationals it is THB 50,000 a month.
• Every 90 consecutive days in Thailand you report your address (TM.47); a late report costs THB 2,000.
• Income from work performed in Thailand is taxed in Thailand from day one, even if the salary is paid by the parent company abroad. A split-payroll arrangement does not change that.
• Social security is compulsory for foreign employees too. From 2026 the wage ceiling is THB 17,500, so the maximum contribution is THB 875 a month from each of employee and employer.
• Your home country's rules continue to apply to social security and tax; plan both sides before the assignment starts.

Sending an employee to Thailand is not "getting a visa". It is five tracks running at once: visa, work permit, immigration reporting, tax and social security, with separate obligations and deadlines for the company and for the individual. I coordinate these assignments for foreign companies at our Bangkok office, and the three things that go wrong most often are the same every year: the parent company believes that paying the salary from home keeps it out of Thai tax, the expatriate flies home without a re-entry permit and loses the extension, and the Thai subsidiary files for a work permit before it has the Thai headcount to support it.

This guide sets out, under the rules in force in October 2026, what a foreign employee and the employer have to do from before departure to the end of the assignment.

1. The documents a foreigner needs to work in Thailand

Under the Immigration Act B.E. 2522 (1979) and the Emergency Decree on the Management of Foreign Workers B.E. 2560 (2017), a foreigner working in Thailand must hold all of the following:

Two misconceptions we hear constantly:

"I am employed by the parent company and only seconded to the Thai subsidiary, so I do not need a work permit." Wrong. The work permit regulates the act of working inside Thailand, regardless of who pays the salary or who signed the employment contract. Attending meetings to give instructions, supervising a production line and signing off documents are all "work" once you are physically in Thailand.

"I will enter visa-free and convert to a Non-B after arrival." Conversion inside Thailand is at Immigration's discretion, slow, and often refused. The correct order is: the Thai company obtains a WP.3 pre-approval letter from the DOE, you apply for the Non-B at the Thai embassy in your country with that letter, and you collect the work permit after entry.

The main exception is a graduate of a Thai university holding the ED Plus student visa, who may apply to stay for up to a year after graduation and, once hired, change to a work category inside Thailand. The student visa rules are in Thailand Student Visa 2026: Non-ED and ED Plus for American and Other Foreign Students, Extensions, Re-entry Permits and the Language School Crackdown .

2. The Non-B visa: apply at home

2.1 Where and which type

• Apply at the Thai embassy or consulate in your home country, in most countries through the Thai e-Visa portal.
• Single entry: valid for three months, 90 days' stay on entry.
• Multiple entry: valid for one year, 90 days per entry. Most assignees take a single-entry visa and apply for the one-year extension after arrival.
• Fees follow each post's current schedule, roughly THB 2,000 equivalent for single entry and THB 5,000 for multiple entry.

2.2 Documents (the employee)

• Passport with at least six months' validity.
• An employment or invitation letter from the Thai company stating position, salary and assignment period.
• The DOE's WP.3 pre-approval letter.
• The Thai company's documents: company affidavit, shareholder list, VAT registration, latest financial statements, social security employee list.
• Educational certificates and evidence of work experience. Many posts require the degree to be legalised in the issuing country and then endorsed by the Thai embassy.

A note on legalisation: Thailand deposited its instrument of accession to the Hague Apostille Convention on 30 June 2026 and the Convention enters into force for Thailand on 28 February 2027. From that date, documents from other Convention countries, which include the United States, Japan, Korea and the EU, will need only an apostille instead of consular legalisation. Documents from non-Convention jurisdictions will continue to go through the embassy.

3. The work permit: the company has to clear three thresholds first

3.1 Thresholds for an ordinary Thai company

The point at which foreign companies most often get stuck: the subsidiary has just been set up, the Thai staff are not yet hired, and head office wants to send its manager to "open up". The 4-to-1 ratio fails and the application is returned. The practical routes:

• A BOI-promoted company is exempt from the ratio and the capital threshold and can use the BOI One Stop Service, which in practice issues permits in one to three working days.
• Without BOI, a representative office or branch can apply under relaxed ratios, but a representative office may not earn revenue.
• For short emergency technical work of up to 15 days, the company notifies the DOE of "urgent and necessary work"; no permit is needed, but the notification must be made in advance, and one extension of up to 15 days may be requested before the period ends.
• The capital, shareholding and nominee issues behind these thresholds are in our guide to setting up a company in Thailand for foreign investors .

3.2 e-Work Permit: online since 13 October 2025

• The Thai company registers on the DOE's online system as a juristic person; the authorised person verifies identity through the ThaID app.
• Upload the company documents, the employee's passport, visa, photo, degree and medical certificate.
• Without complications, issuance takes about 14 days from submission in practice.
• Filing is electronic; the DOE has allowed paper filing only where the system fails, under notices that have changed several times since the launch, so check the current one.
• The permit runs with the extension of stay, normally one year, and must be renewed before expiry.

3.3 The three limits printed on the permit

The permit names the company, the position and the place of work. Anything outside them is illegal work:

• An employee responsible for both the Bangkok plant and the Chonburi plant needs both addresses on the permit.
• An employee who is also a director of the subsidiary and signs documents needs the permit to cover a director or management position. The director's own exposure is covered in our guide to director liability in Thailand .
• An employee stationed at a customer's site needs that address added, or an amendment.

The consequences of illegal work under sections 101 and 102 of the Emergency Decree:

• The employee: a fine of THB 5,000 to 50,000, deportation and blacklisting.
• The Thai company: a fine of THB 10,000 to 100,000 per foreign employee; for a repeat offence, imprisonment up to one year or a fine of THB 50,000 to 200,000, or both, and a three-year ban on employing foreigners.

3.4 Start and end of employment

• Within 15 days of the employee starting, the company notifies the DOE (section 13 of the Emergency Decree).
• When the employee leaves or is repatriated, the company notifies the DOE within 15 days, returns the permit and states the reason; late notification is fined up to THB 20,000 per person.
• Once the permit is cancelled, the legal basis of the Non-B extension falls away and the employee must leave or change visa category. In practice Immigration allows a short grace period of about seven days, which varies by office; staying beyond it is an overstay.

4. Extension, 90-day reporting, TM.30 and re-entry permits

4.1 The one-year extension of stay based on employment

Within the 90 days of a single-entry Non-B, apply to Immigration for a one-year extension with the work permit, the company documents, proof of salary (the salary on the permit must meet the nationality benchmark) and the company's tax filings for the previous month (PND.1 withholding and PP.30 VAT). The fee is THB 1,900.

4.2 The 90-day report (TM.47)

Under section 37(5) of the Immigration Act, after every 90 consecutive days in Thailand you report your current address to Immigration:

• It can be filed up to 15 days early and up to 7 days late, online, by post or in person.
• A late report is fined THB 2,000; if Immigration finds you first, the Act allows a fine of up to THB 5,000 plus THB 200 for each day of non-compliance.
• Leaving the country resets the count. An employee who flies home every two months may never trigger a report, but the count restarts on every entry.

4.3 TM.30 residence notification

Under section 38 of the Immigration Act, the landlord or the company providing accommodation must notify Immigration within 24 hours of the foreigner moving in. It is the landlord's duty, but when you apply for an extension or file a 90-day report, Immigration will ask for the TM.30 receipt; without it you will be sent to regularise it, and the landlord may be fined. For company housing, have the company file it centrally.

4.4 Re-entry permits

A one-year extension is single-entry by itself. Before every trip abroad you must obtain a re-entry permit (THB 1,000 single, THB 3,800 multiple); leave without one and the extension lapses the moment you exit, and you start again on return. This is the most common and most expensive mistake expatriates make. Take a multiple re-entry permit for the whole assignment.

A retiree on the annual extension faces exactly the same trap; the five long-stay routes for retirees, and their money, insurance and tax conditions, are compared in Retiring in Thailand 2026: Retirement Visa (O-A and O-X), LTR, Thailand Privilege and DTV Compared for American and Other Foreign Retirees .

5. Thai personal income tax: you are a taxpayer from day one

5.1 The principle: where the work is done, not where the salary is paid

Under sections 40(1) and 41 of the Revenue Code, income from employment exercised in Thailand is Thai-source income, wherever it is paid and whether or not the recipient is a Thai tax resident, and is subject to Thai personal income tax.

The three common payroll arrangements therefore end in the same place:

When the Revenue Department audits multinational assignees it compares the salary on the work permit, the social security wage and the income declared. If the permit says THB 50,000, the return says THB 50,000, and the employee is in fact paid another USD 4,000 a month at home, that is under-reporting: tax, a penalty of up to 100% and a surcharge of 1.5% a month.

5.2 Rates and deductions (tax year 2026)

Thai personal income tax is progressive:

The main deductions: a 50% expense deduction on employment income capped at THB 100,000, a personal allowance of THB 60,000, a spouse allowance of THB 60,000 where the spouse has no income, social security contributions in full, and life and health insurance premiums and long-term funds within limits.

5.3 Tax residency and foreign-source income (Por.161)

Anyone present in Thailand for 180 days or more in a tax year is a Thai tax resident. For an assignee:

• Thai employment income is taxed whether you are resident or not, at the same rates; only the deductions differ.
• Income from outside Thailand, such as dividends, rent or investment gains at home: once you are a Thai tax resident, under Revenue Department Order No. Por.161/2566 that income is taxable in the year it is brought into Thailand. An assignee who remits home-country dividends into a Thai account to buy a condominium may be taxed on them. The usual answer is to leave home-country income at home and live on the Thai salary. Income earned before 1 January 2024 is outside the rule under the follow-up Order Por.162/2566.

5.4 The employer's obligations

The Thai company withholds tax from the salary monthly (PND.1, due by the 7th of the following month, or the 15th online) and issues the withholding certificate (50 Tawi) at year end; the employee files PND.91 by 31 March of the following year (8 April online). Before leaving Thailand at the end of the assignment, complete the current year's return and obtain a tax clearance; filing remotely from abroad afterwards is awkward.

6. Social security: compulsory for foreign employees

6.1 Enrolment

Under section 33 of the Social Security Act B.E. 2533 (1990), every employee of a Thai employer is an insured person regardless of nationality. Once the expatriate holds a work permit and starts work, the company must enrol them with the Social Security Office within 30 days.

6.2 Rates and ceiling in 2026

Under the ministerial regulation published in December 2025, the ceiling rises to THB 20,000 in 2029 and THB 23,000 in 2032. The employer's wider obligations, from work rules to severance, are in our guide to Thailand labour law for foreign employers .

6.3 What the expatriate gets

Seven benefits: sickness, maternity, disability, death, child allowance, old age and unemployment. The two that matter most to an assignee are sickness (treatment at the registered hospital at no charge) and old age: an employee who leaves Thailand with fewer than 180 months (15 years) of contributions can claim the old-age benefit as a lump sum, including the employer's share and interest, by applying to the Social Security Office after leaving the job. Unemployment benefit rarely applies, because leaving the job usually means the permit is cancelled and the employee leaves the country.

6.4 Workmen's Compensation Fund

Separate from social security and funded entirely by the employer at 0.2% to 1% of wages depending on the industry's risk class. Work injuries, including on business trips, are paid from this fund; make sure the expatriate is included.

7. The home-country side

Thai compliance is only half of the picture. During the assignment the employee usually remains inside the home country's system as well:

• Social security and pensions at home depend on whether the employment relationship with the parent company continues, whether a totalisation agreement exists with Thailand (Thailand has very few), and the home scheme's rules on overseas secondment. Decide before departure whether the employee stays on the home payroll, moves to the Thai payroll, or both.
• Home-country income tax depends on the residency test at home and on any double tax agreement with Thailand. Most agreements exempt short assignments only where the employee spends fewer than 183 days in Thailand, is paid by a non-Thai employer and the cost is not borne by a Thai permanent establishment; an assignment of a year or more fails the first test, so the agreement's practical function is a credit for Thai tax paid, not an exemption. Nationals of countries that tax worldwide income regardless of residence, the United States above all, need advice at home on how Thai tax interacts with their home filing.
• Health cover at home may lapse or continue by its own rules; check before relying on the Thai social security hospital alone.

Louis Group advises on the Thai side and coordinates with the client's home-country advisers; we do not give advice on another country's tax or social security law.

8. Pre-assignment compliance checklist (for HR)

Frequently asked questions (FAQ)

I am only coming to Thailand for short business meetings. Do I need a work permit?

Attending meetings, negotiations and site inspections falls within the Emergency Decree's exemptions and needs no work permit; visa-free entry or a business visa is enough. Operating machinery, instructing production or signing the Thai company's documents is "work". Urgent technical work of up to 15 days can be notified to the DOE in advance, with one extension of up to 15 days.

The Thai company was just set up and does not have four Thai employees yet. Can I go first?

Not through an ordinary company; the application will be returned. The options are BOI promotion (no ratio or capital requirement), applying through a representative office, or hiring and enrolling four Thai employees first.

My salary is paid by the parent company at home. Is it taxed in Thailand?

Yes. Section 41 of the Revenue Code looks at where the work is performed. Salary for work in Thailand is Thai-source income whoever pays it and wherever it is paid.

I go home every month. Do I still have to file the 90-day report?

The report counts consecutive days in Thailand and the count resets on exit. An employee who leaves every two months never reaches 90 days, but must hold a valid re-entry permit before every departure.

Do I have to join Thai social security? What about my scheme at home?

Thailand: an employee of a Thai company holding a work permit is compulsorily insured, with a maximum employee contribution of THB 875 a month in 2026. Home: whether you stay in your home scheme depends on your continuing employment relationship and your country's rules; the two are not mutually exclusive.

Can I get my Thai social security contributions back when the assignment ends?

With fewer than 15 years of contributions you can claim the old-age benefit as a lump sum, including your own and the employer's contributions plus interest, by applying to the Social Security Office after leaving the job.

What happens if I leave Thailand without a re-entry permit?

The one-year extension lapses when you exit, and you have to start again on return. Obtain a multiple re-entry permit (THB 3,800) at the time of the extension.

Can the Thai tax I pay be credited at home?

Usually yes, under your country's foreign tax credit rules and any double tax agreement with Thailand, on production of a Thai tax payment certificate. The agreement's 183-day exemption rarely applies to assignments of a year or more. Take advice at home on the mechanics.

How Louis Group can help

The three failure points are always the same: assuming salary paid from home is outside Thai tax, flying home without a re-entry permit, and filing for a work permit before the Thai headcount exists.

Louis & Partners Thailand in Bangkok handles the whole sequence for foreign employers and their assignees, from the WP.3 pre-approval, the Non-B, the work permit and the extension to 90-day reporting and tax filing, and coordinates with the client's home-country advisers on the other side. If you are planning an assignment to Thailand, contact us before the employee books the flight.

Author: Sirikamon Kaewkragai , Clients Coordinator, Louis & Partners Thailand (Bangkok); visa, work permit and corporate compliance desk for foreign clients. Legal review: Louis Group Taiwan.

*This article reflects Thai law and the practice of the authorities as of October 2026. It is general information, not legal advice; requirements differ between Immigration and Department of Employment offices, so take advice on your own case.*

Related reading

• Setting Up a Company in Thailand 2026 for Foreign Investors: The 49% Rule, Nominee Shareholder Risk, Capital and Work Permit Ratios, BOI and the New DBD Checks
• Thailand Labour Law 2026 for Foreign Employers: Minimum Wage, Working Hours, Leave, Severance, Social Security and Work Rules Explained
• Director Liability in Thailand 2026 for Foreign Directors: Civil Exposure, Criminal Risk, Signing Authority and the Work Permit Trap