How a Thai Work Permit fits with the visa, 90-day report and tax ID
Foreigners working in Thailand operate inside a four-document system that must stay synchronized. The non-immigrant B visa (issued by a Thai embassy abroad or extended by Immigration in Thailand) authorizes stay for the purpose of employment; without it, work permit application cannot start. The work permit (issued by the Ministry of Labour) authorizes the specific job, employer, position and workplace address — changing any of these requires an amendment. The 90-day report (filed with Immigration every 90 days during continuous stay) confirms current address and is a separate compliance line. The Thai personal tax identification number (issued by the Revenue Department once monthly income exceeds the threshold, typically within 60 days of starting work) ties the worker into the PIT system. All four documents share data points: passport number, employer name, workplace address. A mismatch — for example, a work permit issued for 'Bangkok' but the employer moves the office to Nonthaburi — triggers a 30-day amendment window or risks a fine at the next 90-day report. Our office monitors these synchronization points and warns clients before any inconsistency triggers a penalty.
Standard versus BOI work permit timelines
- Standard company at OSSC Chamchuri Square — first work permit: 7 working days after complete file submission; renewal: 5 working days; change of job/employer: 10 working days; capital requirement 2M THB per foreign hire and 4 Thai employees per foreign hire.
- BOI-promoted company at BOI OSSC Vibhavadi — first work permit: 3 working days using SMART Visa channel; renewal: 1–2 working days; capital and headcount thresholds waived by the BOI promotion certificate.
- Treaty of Amity (US citizens) — 5 working days, capital requirements waived under the 1966 Treaty; documentation chain still includes MFA-legalized degree and the Treaty registration certificate.
- Eastern Economic Corridor (EEC) and IEAT industrial-estate factories — 5 working days through provincial Employment Offices, with EEC-S visa option that bundles visa + work permit + 90-day exemption.
- Urgent Work Permit (15-day temporary) — issued same day in genuine emergency (technical fault, urgent installation) on submission of urgent-need letter from employer and Thai counterpart; capped at 15 days non-renewable.
Documents we handle on the employee side
Our office assists with the employee-side document chain that often delays applications: (1) Degree certificate — must be apostilled (if from a Hague country) or legalized at the Thai embassy in the issuing country (non-Hague), then translated into Thai and certified at the Thai MFA; for clients without time to send originals back home, we coordinate with the relevant Thai embassy abroad to issue an interim verification letter accepted by OSSC. (2) Curriculum vitae in Thai — must follow the Department of Employment template, listing each prior employer with dates, position, duties; we draft the Thai version from the English original. (3) Letter from current/last employer confirming employment dates and position — apostille or legalization needed if issued abroad. (4) Marriage certificate (if applying as accompanying spouse later applying for own work) — legalization and translation chain. (5) Birth certificates of accompanying children — legalization and translation for the dependent O visa extension that often runs in parallel. (6) Police Clearance Certificate from country of nationality — required for sensitive sectors (childcare, finance, healthcare) and increasingly requested by Thai employers for executive hires.
Common reasons work permit applications get returned
- Job title mismatch between the visa application and the work permit form — Immigration accepted 'Manager' on the visa but the work permit application says 'Director'; OSSC will return for amendment.
- Workplace address differs from registered office without an amphur-registered branch office filing — OSSC will require a Form Sor Por Por 7 branch registration or relocation of the registered office before issuing.
- Salary stated lower than the Ministry of Labour minimum salary table by nationality (USD/EU/JP/KR/etc.) — currently USD 50,000+ per year for first-tier nationalities; under-salaried applications are returned without prejudice.
- Outdated company affidavit — the DBD-stamped affidavit must be issued within 6 months; older affidavits are rejected and clients must order a fresh one from DBD.
- Educational document translation missing the translator's letterhead, name and license number — OSSC requires this specific format; informal translations are returned.
Bundle services and post-issuance compliance
Our work-permit bundle starts with a 30-minute eligibility screening (free of charge) where we map the client's nationality, visa status, degree, salary and employer to the correct application channel (standard OSSC, BOI, Treaty of Amity, EEC, IEAT, SMART Visa). After eligibility confirmation we quote a fixed bundle covering: employer document gathering (DBD, VAT, Social Security, tax ID), employee document gathering (degree legalization chain, Thai CV drafting, photos, contract), OSSC filing and follow-up, picking up the issued blue book, and a calendar of renewal/90-day-report dates synchronized with the visa. Post-issuance we offer ongoing compliance for ฿18,000–฿28,000 per year covering 90-day reports filed online by us, work-permit renewal 30 days before expiry, and amendment filings for any job, employer or workplace change.
