Quick Facts
Business Visa at a glance
Criminal Offence
Working in Thailand without a valid work permit is a criminal offence under the Foreign Workers' Management Act. Penalties include fines of up to ฿100,000, immediate deportation, and a ban from re-entry. The 2025 enforcement crackdown has significantly increased inspections at co-working spaces and serviced offices across Bangkok and Chiang Mai.
Working legally in Thailand for a Thai company requires two distinct authorisations. The Non-Immigrant B (Business) visa gives you the right to enter and remain in Thailand for work purposes. The Thai Work Permit gives you the right to perform paid employment. Both are mandatory — neither is valid without the other.
Section 1
Non-Immigrant B Visa
The Non-Immigrant B visa must be obtained from a Royal Thai Embassy or Consulate outside Thailand before arrival. Your employer supplies the sponsorship documents. The initial single-entry Non-B is valid for 90 days. Once the work permit is issued, it can be converted to a 1-year multiple-entry Non-B inside Thailand.
A deficient sponsorship package or out-of-date company documents are the most common reasons embassy applications are delayed or rejected at first review. The employer must ensure all documents are current before the application is lodged.
Employer Sponsorship Documents
Section 2
Thai Work Permit
Work permit applications are lodged in person at the Department of Employment (DOE) within 30 days of entering Thailand on a Non-B visa. The permit specifies the employer, position and workplace address. Changing employer requires a new permit. The permit must be renewed annually in line with the Non-B visa.
The 4:1 Employee Ratio
For each foreign employee the company employs, it must maintain at least four registered Thai employees on payroll. The ratio applies to total company headcount, not per department. Companies that fall below this ratio at work permit renewal risk having the renewal denied — leaving the affected employee without valid work authorisation.
4 : 1
Thai : Foreign employees required
฿18,000
Minimum Thai employee monthly wage
30 days
Window to apply for work permit after entry
Permitted Work Only
The work permit lists the exact job title and employer. Performing work outside this scope — even within the same company — is a violation. Certain professions are reserved for Thai nationals only under Annex 1 of the Working of Foreigners Act and cannot be placed on any work permit. These include accounting, driving, bricklaying, carpentry, haircutting, shop assistant work, and several categories of agricultural labour.
Section 3
BOI-Promoted Fast-Track
Companies with Board of Investment (BOI) promoted status benefit from a streamlined visa and work permit process through the One Stop Service Centre at Chamchuri Square in Bangkok. BOI companies are exempt from the standard 4:1 ratio and applications are typically processed in 3 business days.
Ratio Exemption
BOI companies hire foreign staff without the 4:1 Thai employee constraint, enabling international teams to operate without headcount planning.
3-Day Processing
Visas and work permits through the BOI One Stop Service Centre at Chamchuri Square are typically processed in 3 working days — versus 4–6 weeks at the standard DOE route.
Annual Multiple-Entry Non-B
BOI-promoted companies can sponsor 1-year multiple-entry Non-B visas from the outset, skipping the 90-day single-entry step entirely.
SMART Visa Alternative
Senior executives, researchers and investment fund managers at BOI-promoted companies may qualify for a 4-year SMART visa — no work permit required.
Section 4
Consider the LTR Visa Instead
If you earn USD 80,000 per year or more from a foreign employer with annual revenues above USD 50 million, the LTR (Long-Term Resident) visa is almost certainly a better path. It removes the work permit requirement entirely for remote work, provides a 10-year multiple-entry visa, and carries significant tax advantages on foreign-sourced income under Royal Decree 743.
Earning Over USD 80k from a Foreign Employer?
The LTR beats the Non-B route.
No work permit required for remote work
No 4:1 employee ratio constraint
10-year multiple-entry visa
Annual immigration reporting (not 90-day)
0% Thai income tax on foreign-sourced income
Digital work permit included (Highly Skilled category)
Common Mistakes
Five errors that create problems
Working informally before obtaining both authorisations
The Non-B visa and the work permit are two separate documents and both are mandatory. Starting employment without either — or with one but not the other — is a criminal offence under Thai law.
Missing the 30-day window to apply for the work permit
Once you enter Thailand on a Non-B visa, the work permit application must be lodged at the Department of Employment within 30 days. Failing to do so results in a gap in your work authorisation and requires a fresh entry.
Employer headcount falling below the 4:1 ratio at renewal
If the employer reduces Thai staff or hires additional foreign employees, the ratio may fall short at work permit renewal. The renewal can be denied, leaving the foreign employee without valid authorisation.
Changing employer without a new work permit
A Thai work permit specifies the employer, position and workplace. Moving to a new company — or the same company with a different legal entity — requires a new permit. Working for a new employer on an old permit is a violation.
Working outside the scope of the permit
The work permit lists the exact job title. Performing duties outside that scope within the same company, or at an address not listed on the permit, is a breach. Certain professions are entirely reserved for Thai nationals and cannot appear on any foreign work permit.
Questions & Answers
Common questions about the Non-B and work permit
Do I need a Non-B visa and a work permit, or just one of them?
Both are mandatory and neither substitutes for the other. The Non-Immigrant B visa gives you the right to enter and remain in Thailand for work purposes. The work permit gives you the right to perform paid employment. Holding only one — entering on a tourist visa and working, or holding an old permit after changing employer — is a criminal offence.
Can I get a Non-B and work permit if I am forming my own company in Thailand?
Yes, but the company must first be properly registered before the sponsorship documents can be prepared. A newly registered company may not immediately meet the 4:1 ratio, which affects work permit eligibility. BOI promotion can remove the ratio constraint for eligible businesses. We advise on the most efficient company formation and work authorisation structure at the outset.
What happens if I lose my job while holding a Non-B and work permit?
The Non-B visa is tied to the employer who sponsored it. Once employment ends, both the visa and the work permit must be cancelled and you will need to depart Thailand or apply for a different visa category. There is no automatic grace period for finding new employment on the same permit.
Can I work from home or a co-working space on my work permit?
The work permit specifies the workplace address. Working from a location not listed on the permit is technically a breach. In practice, employers registered at a fixed office address should ensure the permit reflects any changes to the working location. The 2025 enforcement crackdown has increased inspections at co-working spaces in Bangkok.
Is there a route that removes the work permit requirement entirely?
Yes — the LTR (Long-Term Resident) Visa for Remote Professionals. If you earn at least USD 80,000 per year from a foreign employer with annual revenues above USD 50 million, the LTR removes the work permit requirement for remote work, provides a 10-year visa, and includes significant tax advantages on foreign-sourced income under Royal Decree 743.
Lawyers for Expats Thailand
We handle Non-B visa applications, work permit filings, BOI One Stop Service submissions and multi-employee visa programmes for businesses operating across Thailand.
See how we help — Business Visa service page →Related Guides
LTR Visa — Reference Guide
→10-year visa, Royal Decree 743 tax exemption, four eligibility categories and application process.
DTV Visa — Reference Guide
→5-year multiple-entry for remote workers and soft-power applicants. Lower financial thresholds.
Extensions & 90-Day Reporting
→Annual visa extensions, TM30 registration, re-entry permits and what happens if you overstay.
Compare All Visa Options
→Every long-stay Thailand visa route compared side by side.
