Southeast Asia’s deepest school market — with a built-in quality floor.

Bangkok dominates, but not completely. Thailand has 166 international schools regulated by the Office of the Private Education Commission (OPEC); the International Schools Database lists 105 in Bangkok. The rest cluster where expats and affluent Thai families live: Phuket, Chiang Mai, and the Eastern Seaboard towards Pattaya. ↗

It is a Thai market as much as an expat one. Roughly 70 per cent of Shrewsbury Bangkok’s ~2,450 students are Thai nationals. Local demand is what sustains the premium tier — and what keeps waitlists long at the best-known schools even when expat numbers dip. ↗

The premium tier is genuinely expensive. NIST’s 2026/27 tuition reaches THB 1,132,800 and Shrewsbury’s THB 1,256,700 — before one-time entrance fees of THB 225,000-265,000. Bangkok’s top schools now price against Singapore, not against the region. ↗

Geography decides the shortlist. Bangkok’s traffic is the structuring fact of family life: families pick a school cluster first — Sukhumvit, Nichada Thani/Nonthaburi, Bang Na, Riverside — then housing inside it. The same logic applies in Phuket (north island vs Rawai) and is why school bus networks (THB 40,000-90,000 per child per year, more at ISB) matter so much. ↗

International schools are licensed by the Ministry of Education through the Office of the Private Education Commission (OPEC). On top of licensing, the Office for National Education Standards and Quality Assessment (ONESQA) conducts external quality assessment of all OPEC-regulated schools. ↗

The rule that does the quality work: by law, every international school in Thailand must secure accreditation from a recognised overseas agency by the end of its fifth year of operation — and must also undergo ONESQA accreditation. OPEC-recognised accreditors include WASC, CIS, COBIS, NEASC, Cognia, MSA-CESS, ISI and EDT. ↗

The practical takeaway for parents: there is no public Thai-language-inspection league table to lean on, so the two-line check is your filter. One — is the school on OPEC’s licence list? Two — which recognised overseas accreditation does it hold, and when was it last renewed? A school that cannot answer both crisply is telling you something.

British is the default: the English National Curriculum to IGCSE, then either A-levels or — increasingly — the IB Diploma in the sixth form (Bangkok Patana’s model, and BISP’s dual IB/A-level offer in Phuket). The full IB continuum is well represented: NIST was the first school in Thailand with triple CIS+NEASC+ONESQA accreditation, and ISB was the first school in the country to offer the IB Diploma at all. American-curriculum schools (ISB, Ruamrudee, QSI’s mastery-learning network) serve US-bound families. ↗

Curriculum choice drives portability to the next posting — our IB vs British vs American guide walks the trade-offs. One Thailand-specific wrinkle: the accreditation rule means curriculum branding is backed by external review here more reliably than in most of the region.

We pull figures from published schedules, not brochures. The 2025/26-2026/27 anchors: ↗

• Bangkok Patana (founded 1957, not-for-profit; IGCSE then IB Diploma): THB 495,000 (Nursery) to THB 975,000 (Year 12) in 2025/26, plus a THB 250,000 entrance fee. ↗
• NIST (full IB continuum, not-for-profit): THB 650,200-1,132,800 in 2026/27, plus a THB 265,000 registration fee and either a THB 575,000 refundable deposit or THB 60,500 annual fund payment.
• Shrewsbury Riverside: THB 669,600-1,208,400 in 2025/26, rising to THB 696,300-1,256,700 in 2026/27, plus a THB 225,000 Guaranteed Place Fee.
• ISB: THB 640,000 (Pre-K) to THB 1,162,000 (high school) in 2025/26, plus THB 260,000 registration — and distance-banded bus fees of THB 108,000-172,800.
• Harrow Bangkok: THB 553,100-1,037,100 in 2025/26 with a THB 225,000 admission fee.

Below the premium tier, Bangkok’s mid-market (Patana’s younger years, Ruamrudee at THB 538,400-786,000, St Andrews) runs roughly THB 400,000-600,000, and budget international schools start around THB 200,000-350,000. The one-time stack matters as much as tuition: entrance fees, deposits and capital levies routinely add THB 300,000-800,000 to year one at premium schools.

Phuket is a real market, not a fallback. The island has 15-plus international schools. British International School, Phuket (founded 1996, CIS-accredited, about 1,400 students of 50-plus nationalities) offers British to IGCSE then a dual IB/A-level sixth form with boarding, at THB 470,000-935,000+ for 2026-27. UWC Thailand runs the IB continuum with boarding and a scholarship engine at THB 345,000-933,000. HeadStart (British, two campuses) covers the mid-market at THB 347,000-540,000. ↗

Chiang Mai trades prestige for cost and calm. The north’s established names — Chiang Mai International School (American, WASC, founded 1954), Lanna International (British, WASC) and Grace International — sit at fee levels well below Bangkok’s mid-market, which is why the city draws long-stay expat and remote-working families. Senior-years depth is thinner: check the exact IGCSE/A-level/IB pathway before committing past age 14. ↗

The Eastern Seaboard has a boarding outpost. Rugby School Thailand (opened 2017, Chonburi) offers British schooling with boarding towards Pattaya — an option for families posted to the industrial east who do not want a Bangkok commute. ↗

Every fee figure, statistic and policy claim above traces to our research dossier. Primary sources: ISAT (the accreditation rule and recognised accreditors), school fee schedules from Bangkok Patana and Shrewsbury, and the Thailand Board of Investment’s Cost of Doing Business report, which quotes official fee schedules for NIST, ISB, Harrow, Ruamrudee and Patana. Secondary reporting: International Schools Database, SchoolIntel, and named regional guides attributed as reported experience.

Fees and policies expire. This page was researched on 2 September 2026 and is re-verified each academic year — see our research standard for how claims are graded, and corrections if you spot something stale.