A foreign employee seconded from an overseas branch into a Thai entity generally needs a standard Non-Immigrant B (Non-B) visa and a full work permit before they can legally start work [ogletree.com]. There is no shortcut category that lets HR skip this process just because the assignment is temporary. Understanding which requirements apply is where most secondment mistakes happen.
TL;DR
- Seconded employees generally need a Non-B visa plus a separate work permit before working in Thailand [ogletree.com].
- Business meetings, seminars, and exhibitions are exempt from work permit rules, but this exemption does not cover actual productive work.
- Short-term technical or urgent assignments may have limited alternative pathways, but HR teams should confirm the specifics with a qualified immigration adviser rather than assume a shortcut applies.
- Working without a permit carries penalty risk for the individual, including fines and possible deportation.
- Employers also face penalty exposure for sponsoring or allowing unauthorized work.
About the Author: Issa Compass is a real-time visa platform that assists with Thai immigration processes, including Non-B applications and work permits for companies based in Bangkok that do not require a specific operating license. This article draws on that operational experience with employment-based visa categories and the compliance questions HR teams raise most often.
What exactly is a cross-border secondment, and why does Thailand treat it differently from a transfer?
A secondment is a temporary work assignment where the employee stays employed by their home-country entity while working, often physically, for a related or partner organization abroad [ogletree.com]. In many jurisdictions, this arrangement gets its own visa lane, an intra-company transfer permit, because the employee is not being locally hired, just temporarily deployed. Thailand's treatment of secondments for visa purposes centers on a single question, is the person performing work in Thailand, and if so, they generally need standard employment authorization [ogletree.com]. Legally, this sometimes means the employment relationship with the home entity must be adjusted, placed into what's often called a "sleeping" arrangement, while the Thai entity temporarily takes on the sponsoring role [littler.com]. Global mobility teams that assume secondment status alone provides legal cover in Thailand are working from a false premise, and it's a costly one given the penalty structure discussed below.
When can a secondee actually work in Thailand without a full work permit?
Building on the point above, there are narrow paths that do not require the full Non-B and work permit process. The first is attendance-only: foreign nationals attending business meetings, seminars, and exhibitions without engaging in hands-on work are generally treated differently from those performing productive labor [ogletree.com]. This covers observing, discussing, and negotiating, but not producing deliverables, operating machinery, training staff, or doing hands-on technical work. The line is about function, not job title. HR teams should confirm the exact scope of any such exception with a qualified immigration adviser before relying on it, since the specifics of short-term or urgent work authorization pathways can vary and should not be assumed without verification. Outside of clearly attendance-only scenarios, a secondee doing substantive work in Thailand needs the standard process.
What does the standard Non-B visa and work permit process actually require?
Since the exceptions above are narrow, most secondments longer than a few days end up needing a Non-B visa. This is the standard employment visa category, and applicants should confirm the current documentation requirements, such as passport validity, proof of finances, and sponsoring-entity paperwork, directly with the relevant Thai authority or a qualified immigration adviser [ogletree.com]. It's worth being precise here: the Non-B visa itself does not, on its own, authorize work. The holder must obtain a separate work permit before starting any employment activity [ogletree.com]. Two documents, two approvals, one sequence.
On the company side, sponsoring a foreign employee under a Non-B comes with structural requirements that HR teams frequently underestimate, including registered capital thresholds and Thai-to-foreign employee ratios. These requirements should be confirmed directly with a qualified immigration adviser or the relevant Thai authority, since the exact figures can vary and should not be assumed.
Foreign Business Act ownership rules are a separate, unrelated consideration that governs which business activities foreigners can engage in, not a Non-B visa requirement, so don't conflate the two when scoping a secondment plan.
Does BOI promotion change the equation for a secondment?
A related but distinct question is whether the sponsoring entity's regulatory status can simplify any of this. Companies promoted by the Board of Investment are exempt from the standard 4:1 ratio requirement. It is not yet clear from available guidance whether other requirements, such as registered capital or SSO contributions, are also waived, so HR teams should confirm the full scope of any exemption with that entity's BOI liaison rather than assume broader relief applies. BOI status does not create a separate secondment visa category. For BOI-promoted companies, the stay extension and work permit are typically filed together through the relevant one-stop service channel, which is a procedurally different path from the standard Non-B and work permit sequence used outside Thailand. HR teams managing a secondment into a BOI-promoted Thai entity should confirm exactly which exemptions apply and which filing process to use with that entity's BOI liaison, since promotion certificates vary by activity and industry.
What happens if a secondee works before the paperwork clears?
Stepping back from the process detail, the harder question for HR is risk exposure if a secondee starts working, or even appears to be working, before authorization is in place. Working without a valid permit carries penalty risk for the individual, which can include fines and, potentially, deportation and restrictions on future work authorization. Employers also face penalty exposure for sponsoring or allowing unauthorized work, with consequences that can escalate for repeat violations. Companies should confirm the current specific penalty amounts and consequences with a qualified immigration adviser rather than rely on assumed figures. For a company running a portfolio of secondments across multiple markets, one non-compliant assignment in Thailand can create real risk for the entire pipeline of future foreign hires into that entity.
How should HR teams structure a short-term Thailand secondment to stay compliant?
Given the penalty exposure, planning ahead beats reacting. A few practical habits separate HR teams that handle Thailand secondments cleanly from those that get caught out:
- Classify the assignment honestly at the outset: is it attendance-only, a possible short-term technical exception, or genuine ongoing work requiring a full Non-B and permit
- Confirm the Thai sponsoring entity meets the applicable structural requirements, or has BOI exemptions, before committing to an assignment start date, and verify the specifics with a qualified immigration adviser
- Never treat "the employee is only here for a few weeks" as a reason to skip authorization; duration alone should not be assumed to create an exemption
- If a foreign employee needs to move between the company's branch offices in Thailand, confirm with a qualified immigration adviser whether the existing work permit covers the new location or whether additional filing is required
- Build in lead time; secondments planned around a fixed start date without buffer for document collection and processing are the most common source of last-minute non-compliance
Think of the classification step like a triage nurse assessing severity before treatment: get the category wrong at the front door, and everything downstream, timeline, documentation, cost, is built on a false premise.
Frequently Asked Questions
Does a secondment agreement with the home-country employer satisfy Thai visa requirements?
No. A secondment agreement documents the employment relationship but does not substitute for a Non-B visa or work permit. Thai immigration authorizes work based on the sponsoring Thai entity's application, not on the terms of a home-country contract.
Can a secondee work remotely for their home entity while physically in Thailand without a work permit?
This depends heavily on the specifics of the arrangement and the nature of the work, and falls outside a standard secondment analysis. HR teams considering this setup should get a case-specific review rather than assuming remote work removes the permit requirement.
How long does the Non-B visa and work permit process typically take?
Timelines vary by embassy, visa category, and current workload, with some embassies meaningfully slower than others. Check the Issa Compass app for current estimates rather than assuming a fixed number of business days.
Are there any short-term or urgent work authorization pathways available?
There may be limited alternative pathways for short-term or urgent work, but HR teams should confirm the specifics, including any duration limits or renewal restrictions, with a qualified immigration adviser rather than assume a shortcut applies. Anything beyond a genuinely short, clearly-defined task should move to the standard Non-B and work permit route.
Does BOI promotion mean a company can skip the work permit entirely for secondees?
No. BOI promotion can waive the standard 4:1 Thai-to-foreigner hiring ratio, but the seconded employee still needs a Non-B visa and work permit, typically filed through the BOI's dedicated process rather than the standard route.
What is the difference between a Non-B visa and a work permit?
The Non-B visa is the immigration document allowing entry and stay; the work permit is the separate authorization to actually work. Holding a Non-B without a work permit does not authorize employment.
Can Issa Compass handle a Non-B application for a secondee?
Issa Compass files Non-B visas and work permits only when the company is based in Bangkok and the business does not require a specific operating license to operate; if either condition is not met, Issa Compass is not able to assist with this category. Companies outside Bangkok, or licensed businesses like restaurants, need a different provider for this category.
About Issa Compass
Issa Compass is a real-time visa platform, not a government agency or law firm, built to make Thai immigration processes clearer for individuals and the companies that sponsor them. Its decision engine checks applications against live embassy requirements, flagging risk factors before submission rather than after a rejection. For Bangkok-based companies whose business does not require a specific operating license, Issa Compass assists with Non-B visa Thailand filings and work permit steps, working alongside immigration consultants and a legal team to keep the process moving. The Issa Money-Back Guarantee applies to Full Service applications that are pre-qualified and meet all of Issa Compass's published eligibility conditions, which may include factors such as home country citizenship or residency status, criminal record, and whether the filing is a reapplication or through a third country; certain embassies and visa routes are excluded. The guarantee, where applicable, covers the Issa service fee and does not cover the government or embassy fee. Full terms are available on the Issa Compass site.
If your company is planning a short-term assignment into Thailand and needs clarity on which visa category actually applies, explore Thailand's visa options or get in touch through Issa Compass to talk through your specific situation.
