Do you really need four Thai staff per work permit?

Key Takeaways

• The 4 Thai staff to 1 foreign work permit ratio is applied at the counter, but we could not find it written in any law, regulation or notification, after a genuinely thorough search.
• The capital rule everyone quotes alongside it is different: THB 2 million paid-up capital per work permit does trace to a named instrument, the Department of Employment’s own Regulation.
• BOI promotion replaces both tests. A BOI company gets its people in through Sections 24 to 26 of the Investment Promotion Act instead.
• The paper work permit is gone. The e-Work Permit system has been mandatory since 13 October 2025, with paper only accepted in narrow cases until 28 July 2026.

In Detail

Who can even sponsor one

Only a Thai-registered juristic entity can sponsor a foreign employee’s work permit: a Thai limited company, a branch, a representative office, or a BOI-promoted entity. There is no route that lets an individual or a foreign company sponsor a permit directly.¹ If you have not yet incorporated, you do not yet have a sponsor, whatever your visa status.

The 4 to 1 rule: the number everyone in this subject repeats

Ask any incorporation agent, law firm or relocation consultant about hiring foreign staff in Thailand and you will hear the same figure within a minute: 4 Thai employees for every 1 foreign work-permit holder, applied to a non-BOI Thai limited company at the point the Department of Employment reviews the application.² It is also described as an ongoing obligation rather than a one-time check, meaning a company sponsoring 4 foreign staff is expected to be able to show 16 Thai staff, not 4.³

We looked for where it comes from. It is not there.

Before repeating a figure this consequential, we tried to find the instrument that states it. We read the Emergency Decree on the Management of Employment of Foreign Workers in full, Sections 59 to 74, the chapter that governs work permits. No ratio appears anywhere in it. We then read the Department of Employment Regulation B.E. 2552 (2009), the instrument that Thai government sources themselves cite as the legal basis for work permit criteria. It sets out capital thresholds and a list of exemption categories. It states no staffing ratio either.

We ran seven separate search routes across English and Thai, targeting the Department of Employment, the Ministry of Labour, and the Royal Gazette by name, plus general and immigration-specific sources. No Royal Decree, Ministerial Regulation, Department of Employment Notification, or Gazette entry surfaced stating a numeric 4 to 1 ratio. The only places the figure appears attached to an official body at all are pages describing what the Long-Term Resident visa and BOI promotion are exempt from, and none of those pages cites a source for the rule they name.

Practically, this changes nothing about how you should plan a hiring budget. Assume the ratio applies, because it is applied. It changes what you should do if an adviser tells you it is “the law”: ask them to show you the section. If they cannot, that is not a reason to ignore the rule. It is a reason to stop assuming your adviser has actually checked it either.

The capital rule, by contrast, has an address

The figure usually quoted next to the ratio is a capital test: THB 2 million of fully paid-up registered capital per foreign work permit, rising to THB 3 million per permit where the capital is brought in from abroad, halved to THB 1 million where the foreign employee has a Thai spouse under a legally registered marriage, and capped at 10 permits per company.⁴⁵

Unlike the ratio, this one traces to a named instrument: the Department of Employment Regulation on Criteria for Considering Permission to Work of Aliens, B.E. 2552 (2009). It is worth naming precisely what kind of instrument that is. It is not a Royal Decree, an Emergency Decree provision, or a Ministerial Regulation. It is a Department of Employment internal Regulation, a sub-Ministerial instrument issued under the Department’s own administrative authority. That is a real legal basis, just a lower-ranking one than most commentary implies when it calls this “the law.”

The contrast is the useful part. Two figures get quoted in the same breath, by the same sources, with the same confidence. One has a name, a year, and a quoted clause. The other has neither. Treat them differently.

BOI promotion replaces both tests

A BOI-promoted company does not sit the general Department of Employment ratio or capital test at all. It runs instead on BOI’s own approval, under Sections 24 to 26 of the Investment Promotion Act: Section 24 covers permission for foreign nationals to enter Thailand to study an investment opportunity, and Sections 25 and 26 cover permission to bring in skilled workers and experts.⁶ In practice this runs through BOI’s One Start One Stop Investment Center, which grants work permits tied to specific approved positions such as Expert, Manager or Advisor within the promoted activity, sidestepping the general ratio and capital tests for those approved roles.⁷

This is the cleanest route through everything in this chapter if your business qualifies for BOI promotion at all, which is why read more is worth reading before you plan your hiring.

Por. 8/2568: a real ratio, but only for larger manufacturers

BOI issued Notification Por. 8/2568 in June 2025, setting new criteria for approving, placing and extending expatriate positions in BOI-promoted companies. Unlike the general 4 to 1 rule, this one is a named, dated notification, reported consistently by law firms tracking BOI compliance.⁸

Its headline requirement is a 70 percent Thai-workforce floor, but it applies only to BOI-promoted manufacturing companies with more than 100 employees. Manufacturers and service businesses below that headcount are exempt from this clause entirely, which covers most readers of this guide.⁸

It also sets minimum monthly salary floors for expatriate roles: reported at roughly THB 150,000 for executive positions, THB 75,000 for management (THB 50,000 with a bachelor’s degree), THB 50,000 for operations, THB 75,000 for technical and IT roles (THB 50,000 with a degree), and THB 35,000 for workstation operators, with salaries required to be paid through the Thai entity rather than from overseas.⁸ It phases in from 1 October 2025 for certificates issued after 5 June 2025, and from 1 January 2026 for everyone else already promoted.⁸

The e-Work Permit system is now the only door

The Department of Employment has replaced the paper “Blue Book” work permit with a fully digital platform, e-workpermit.doe.go.th. All new applications, renewals, cancellations and urgent work notifications go through it, and employers must first register and verify their identity through the ThaiID mobile app before applying.⁹¹⁰

The digital system has been mandatory for new applications since 13 October 2025. The Department extended the deadline for accepting manual, paper-based submissions to 28 July 2026, after which the process is digital-only except where the employer can prove a genuine technical fault in the e-Work Permit system itself.¹¹¹² Reported processing time under the digital system is 7 to 10 business days, and applications can be lodged at any time rather than only during office hours.¹⁰

Documents, fees, validity and renewal

The standard sequence is a Non-Immigrant “B” visa obtained outside Thailand first, entry into Thailand, and then the work permit application itself, filed by the Thai employer through the e-Work Permit system.¹³ Core documents commonly required include the applicant’s passport and Non-B visa, the employer’s company affidavit and shareholder list, VAT and Social Security registration, a list of Thai employees with payslips and SSO contributions to evidence the ratio, the foreign employee’s CV and qualifications, and, since the digital rollout, a medical certificate from a Thai hospital dated within one month confirming the absence of prohibited diseases.¹³

The government fee scales with the permit’s duration: roughly THB 750 for under 3 months, THB 1,500 for 3 to 6 months, and THB 3,000 for a full year.¹³ Total practical cost, including any agent or document fees, is commonly quoted in the THB 4,000 to 8,000-plus range.¹⁴ A permit is typically issued to match the underlying visa period, up to a maximum of 2 years, and renewal should be started roughly a month before expiry.¹⁵

There is also a narrow exemption for urgent or specific ad-hoc work that finishes within 15 days, requiring only written notice to the registrar rather than a full permit, with one further 15-day extension available if the work is not finished. Commentary still calls this “the Section 9 exemption,” after the numbering in the old Working of Foreigners Act. Under the current Emergency Decree it sits at Section 61.¹⁶¹⁷

What working without one costs you

The governing penalty instrument is the Emergency Decree on the Management of Employment of Foreign Workers B.E. 2560 (2017).¹⁸ Its original 2017 penalties were severe: employer fines of THB 400,000 to 800,000 per worker, and up to 5 years’ imprisonment plus a THB 100,000 fine for the worker. A 2018 amendment softened both sides of that significantly.¹⁹

Under the current, amended regime, a foreign worker caught working without a permit faces a fine of THB 5,000 to 50,000, deportation, and a 2-year bar on obtaining a new permit.²⁰ An employer who hires a foreigner without a permit, or lets one work outside the permitted scope, faces a fine of THB 10,000 to 100,000 per worker, rising on a repeat offence to up to 1 year’s imprisonment and a fine of THB 50,000 to 200,000 per worker, with a 3-year bar on employing foreign workers at all.²¹ Failing to notify the registrar of a foreign worker’s employment or its end within the required period carries a further fine of up to THB 20,000 per worker.²⁰

What this means for you

Budget for the 4 to 1 ratio as if it were written down, because at the counter it functions exactly as if it were. Budget for the capital rule the same way, but now you know which of the two you could actually hand a skeptical co-founder a citation for. If your business might qualify for BOI promotion, price that route before you price hiring Thai staff purely to clear a ratio you cannot verify the legal basis of. And build the e-Work Permit registration into your setup timeline now. After 28 July 2026 there is no fallback to paper.

Before you plan your foreign headcount

• Is your entity incorporated yet? No Thai-registered sponsor means no work permit application, regardless of visa status.
• Do you have, or can you show, 4 Thai staff for every foreign permit holder you plan to sponsor, on an ongoing basis, not just at filing?
• Does your paid-up registered capital reach THB 2 million per foreign permit you intend to sponsor, or THB 1 million if the employee has a legally registered Thai spouse?
• Have you checked whether your activity could qualify for BOI promotion, which removes both tests in favour of its own approval process?
• If someone tells you the 4 to 1 ratio is “the law,” have you asked them to show you the section? Their answer tells you how carefully they have actually checked their own advice.
• Have you registered for the e-Work Permit system through ThaiID, rather than assuming paper submission will still be available after 28 July 2026?

Sources

23 sources for this article, 3 of them primary. Where we could not verify something, the article says so rather than estimating.

1. Thailand Board of Investment (primary), www.boi.go.th
2. Silk Legal, silklegal.com
3. Belaws, belaws.com
4. ASEAN Briefing, www.aseanbriefing.com
5. Commenda, www.commenda.io
6. BOI One Start One Stop (primary), osos.boi.go.th
7. BOI One Start One Stop (primary), osos.boi.go.th
8. Rajah & Tann Asia, www.rajahtannasia.com
9. Fragomen, www.fragomen.com
10. Siam Legal, www.siam-legal.com
11. The Workers' Rights, www.theworkersrights.com
12. Leap29, www.leap29.com
13. Manpower Thailand, www.manpowerthailand.com
14. The Thaiger, thethaiger.com
15. Themis Partner, thailand.themispartner.com
16. Thai Lawyers, thailawyers.com
17. Thailand Law Online, www.thailandlawonline.com
18. LawPlus, www.lawplusltd.com
19. Antares Group, antaresgroup.com
20. Royal Thai Government, www.thailand.go.th
21. Royal Thai Government, www.thailand.go.th
22. ASEAN Now, aseannow.com
23. Thailand Law Online, www.thailandlawonline.com

This article is general information about doing business in Thailand and is not legal, tax, or financial advice. Every figure is cited with its source and its date. Thai regulation is changing quickly and rules current at publication may change without notice. Confirm anything you intend to act on with qualified Thai counsel.