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Who This Visa Is For

The Non-Immigrant B visa — commonly called the Non-B or business visa — is the standard entry document for foreign nationals who intend to work legally in Thailand for a Thai employer. It is also used for business activities that fall short of employment: attending meetings, conducting negotiations, or setting up a company.

In most cases, the Non-B visa is the precursor to a work permit. Without a valid work permit, holding a Non-B visa does not authorise work. The visa and the work permit are two separate documents, both required to work legally.

For a broader overview of Thai visa options see the Thai visa options hub. This page covers general information only and is not legal or immigration advice.

CMLocals Chiang Mai Locals Business Visa stamp official document non-immigrant

Official Classification

Non-Immigrant Visa Category B (Business/Work). Issued at Thai embassies and consulates abroad for initial entry. Annual extensions of stay are processed at local Immigration offices (e.g., Chiang Mai Immigration) once a work permit is in place.

Validity and Extensions

FeatureDetail
Initial visaSingle or multiple entry; typically 90 days initial permitted stay
Annual extension1 year, tied to valid work permit
Extension conditionMust hold a valid work permit for the same employer. Extension refused if work permit lapses.
Re-entry permitsRequired before leaving Thailand during an extension period. Single or Multiple.
Multiple entry Non-BAvailable from some embassies for specific use cases (e.g., BOI-promoted companies)

The Work Permit Requirement

A Non-B visa alone does not authorise work. A separate work permit (bai anuyat thamngaan) must be obtained from the Department of Employment before beginning any employment. The work permit specifies:

  • The employer (you cannot work for a different employer without a new permit)
  • The job position and duties
  • The province in which you may work

Work permits are employer-sponsored. The employing company must meet staffing ratio requirements (typically 4 Thai employees per 1 foreign employee, though exceptions exist for BOI-promoted companies and certain industries).

Working without a valid work permit in Thailand carries serious consequences including fines, deportation, and a ban on re-entry. This applies even if you hold a valid Non-B visa. Ensure your work permit is active before starting work, and confirm it covers your actual job duties and location.

Employer Requirements

Thai employers sponsoring a Non-B visa and work permit must typically meet these requirements:

RequirementDetail
Company registrationRegistered Thai company (limited company, representative office, or BOI-promoted entity)
Minimum registered capital2 million THB per foreign employee (standard; reduced for some company types)
Thai:foreign staff ratio4:1 (Thai employees to foreign employees) in standard cases
Tax complianceCompany must be tax-registered and filing returns
Revenue Department registrationVAT registration required for some company types

BOI-promoted companies and companies in certain Special Economic Zones may qualify for relaxed staffing ratios and simplified work permit processes. If your employer has BOI status, confirm which rules apply.

Application Process

Initial Non-B visa (from abroad)

  1. Secure a job offer and obtain a formal letter of offer or invitation from the Thai employer.
  2. Apply for Non-B visa at a Thai embassy or consulate in your home country with employer documentation.
  3. Enter Thailand on the Non-B visa (initial 90-day permitted stay).
  4. Employer applies for work permit at the Department of Employment (usually in Bangkok or the relevant provincial office). You must be present for the application.
  5. Once the work permit is issued, apply for a 1-year extension of stay at Chiang Mai Immigration (if based in Chiang Mai).

Annual extension (in-country)

  1. Ensure work permit is valid and renewed before applying for visa extension.
  2. Submit extension application to Chiang Mai Immigration before current stamp expires.
  3. Bring work permit original, passport, TM.7 form, TM.30, employer documents, and copies.
  4. Receive new 1-year extension stamp. Repeat annually.
CMLocals Chiang Mai Locals Business Visa professional workplace education training

Chiang Mai Application Notes

Chiang Mai Immigration (71 Mahidol Road) handles Non-B extension of stay applications for foreign workers based in Chiang Mai province. Work permit applications are handled by the Department of Employment in Chiang Mai — a separate office from Immigration.

Teachers and education sector workers make up a significant portion of Non-B holders in Chiang Mai. Language school teachers, international school staff, and university lecturers are common applicants. ED Visa holders transitioning to a work-based visa may encounter this route.

Bring the original work permit and a letter from your employer confirming continued employment at each annual extension. Chiang Mai officers check the work permit's listed employer matches the sponsoring company.

Pros and Cons for Chiang Mai

Why the Non-B works for Chiang Mai workers

  • The only route for most foreign nationals to work legally in Thailand for a local employer.
  • Annual renewal structure is well understood by Chiang Mai Immigration and local HR departments.
  • Employer handles much of the documentation — reduces individual bureaucratic burden compared to self-sponsorship routes.
  • Stable legal status when work permit and visa are in sync.

Limitations to consider

  • Tied to a specific employer — changing jobs requires a new work permit and typically a new visa process.
  • Employer must meet capital and staffing ratio requirements — small or informal employers may not qualify.
  • Provincial restriction on work permit — you may not legally work in a different province without amending your permit.
  • Annual in-person renewal required at both Department of Employment (work permit) and Immigration (stay extension).
  • Re-entry permit required before international travel during extension period.

A realistic example

A 29-year-old Canadian teacher is offered a full-time position at an international school in Chiang Mai. The school sponsors her Non-B visa — she applied at the Thai Embassy in Ottawa, entered Thailand, and the school's HR department handled her work permit application at the Chiang Mai Department of Employment. She receives a 1-year extension at Chiang Mai Immigration shortly after, tied to her work permit. She renews both documents in the same month each year.

Common Pitfalls and Misunderstandings

  • Starting work before the work permit is issued. This is one of the most common errors. The work permit must be in hand before you begin employment. A visa alone does not authorise work.
  • Changing employers without updating the work permit. The work permit names a specific employer. Moving to a new employer without a new permit is a violation even if you hold a valid visa.
  • Working outside the permitted province. Work permits specify the province. Working from Chiang Mai on a permit issued for Bangkok is technically non-compliant. Many remote work arrangements create ambiguity here.
  • Letting the work permit lapse. If the work permit expires, the visa extension will not be renewed by Immigration. Ensure HR renews the work permit in advance of its expiry date.
  • Assuming a Non-B visa covers freelance or self-employed work. It does not. Freelancers and self-employed individuals face significant barriers to legal work authorisation in Thailand without company sponsorship.

Related Visa Options to Consider

Frequently Asked Questions

Disclaimer – General Thai Visa Advice Only

CMLocals specialises in ED Visas and Volunteer Visas. The Non-B business visa is covered here as part of broader Thai visa advice for Chiang Mai.

Work permit and visa rules in Thailand are complex, employer-specific, and change frequently. The information on this page is general and cannot replace advice from a qualified Thai immigration lawyer or licensed visa service.

Always verify current requirements with the Department of Employment (doe.go.th) and the Thai Immigration Bureau before taking any action.

Last verified: February 2026