Why Bangkok School Applications Require Early Planning
Bangkok's international school market is oversubscribed at the most popular schools and at the most popular year groups. The application process itself is straightforward, but the timeline is not. Families who assume they can apply and start within a term or two of arrival are regularly disappointed. The best practice is to begin the school search 12–18 months before your intended start date, and for NIST in particular, the reality is that places for British families may not become available within 12–18 months regardless of when you apply.
This guide sets out the application process end to end, with timing guidance specific to Bangkok's key schools.
Overview of the Application Process
The standard application pathway for Bangkok international schools follows five broad stages:
- Register interest / submit application (with application fee)
- Assessment — cognitive ability test and English proficiency screening
- Receive offer or Wait Pool notification
- Accept offer — pay entrance/admission fee to secure the place
- Enrolment — submit full documentation; arrange education visa if required
Stage 1: Registering Interest and Application Submission
Application Fees
Most schools charge a non-refundable application fee to process your form:
- Bangkok Patana: THB 4,000
- NIST: THB 6,000 (including assessment fee of THB 2,500)
- Harrow: THB 5,000
- ISB: THB 4,700
These fees are modest relative to subsequent costs, but they are non-refundable. Only apply to schools you have genuinely researched and are prepared to attend.
Application Forms and Required Documents
All major Bangkok international schools now accept applications online. Standard documentation includes:
- Completed online application form
- Copy of child's passport (all pages with stamps, showing current visa if in Thailand)
- Most recent two years of school reports
- Confidential head teacher or class teacher reference (submitted directly by the current school)
- Immunisation records
- Passport photograph
- Any Special Educational Needs (SEN) or EAL documentation
If your child has previously been assessed for learning support, reading age, or speech and language, submit those reports. Schools appreciate full disclosure — it allows them to plan appropriate support, not disqualify applicants.
When to Apply
| School | Advised Application Window for August Start |
|---|---|
| NIST | By mid-December the preceding year. Wait Pool reality: 1–2+ years for popular nationalities |
| Bangkok Patana | October–December, 10–14 months ahead |
| Harrow | Year-round but the earlier the better; Year 7 entry particularly competitive |
| ISB | Year-round; Nichada Thani residency helps in practice |
| Wells / KIS | 3–6 months ahead typically sufficient; less oversubscribed |
The best general window for an August 2027 entry is October to November 2026.
Stage 2: Assessment
CAT4 Cognitive Abilities Test
Most Bangkok international schools use the CAT4 (Cognitive Abilities Test, 4th Edition) for entry from Year 7 (age 11–12) upward. The CAT4 tests verbal, non-verbal, quantitative, and spatial reasoning. It does not test curriculum knowledge, so there is no specific exam preparation curriculum to study. However, familiarity with the test format can be helpful; practice materials are available commercially.
The CAT4 can typically be taken:
- At the school in Bangkok (families in Thailand attend in person)
- At an authorised remote testing centre in the child's country of residence (for families applying from abroad)
- Online under supervised conditions at some schools
Results are used to understand a child's learning profile, not simply to select the highest scorers. Schools assess whether they can meet a child's needs given current year group spaces and support resources.
EAL Screening
Harrow Bangkok screens students for English as an Additional Language (EAL) from Year 6 upward. This is relevant for children who have not been educated in English, or whose English proficiency may need support. Schools with strong EAL programmes — including Patana, NIST, and Wells — can accommodate students whose English is still developing, but they need to know this in advance.
Assessment for Younger Children
For Early Years and primary entry (typically Reception to Year 5), formal cognitive tests are not standard. Instead, schools may invite the child to spend a morning in class, or conduct a brief informal interaction with the admissions team. The primary assessment is often of the family's commitment and the child's social readiness.
Stage 3: Offer or Wait Pool Placement
Following assessment, the school will either:
- Make an offer — a place is available in the relevant year group
- Place on the Wait Pool — the year group is full; the child is queued
NIST's Nationality Cap and Wait Pool
NIST operates a 30% nationality cap per nationality. This means no single nationality can exceed 30% of any year group. For popular nationalities — including British — the quota is often fully committed, sometimes years ahead. Wait Pool placement of one to two or more years is common for British families.
NIST advises registering by mid-December for an August start. However, due to the nationality cap, registering in December does not guarantee a place for the following August — it establishes queue position. Families applying to NIST should treat it as a long-game process and maintain a parallel application to a backup school. See our waiting lists guide for more detail.
Bangkok Patana Waiting Lists
Bangkok Patana has waiting lists for Years 1–3 and Year 7 — the most popular entry points. Years 4–6 and Years 8–11 are more likely to have availability. For Year 7 (secondary school entry), apply no later than October of Year 6, meaning if your child is currently in Year 5 in the UK, you should be contacting Patana now.
Harrow's Waiting-Pool Fee
Harrow charges a Waiting-Pool Fee of THB 225,000 if you are offered a place but elect to defer your start rather than take it immediately. This is a non-refundable fee charged to hold the queue position. Its existence reflects genuine demand — Harrow uses this mechanism to separate serious applicants from speculative ones.
Stage 4: Accepting an Offer and Securing the Place
Accepting a place typically involves:
- Signing the acceptance form within the deadline given (often 10–14 days)
- Paying the entrance or admission fee — this is the largest single upfront cost:
- Bangkok Patana: THB 250,000 (first child), THB 200,000 (second and subsequent)
- NIST: THB 265,000 registration + THB 575,000 Campus Development Fee (refundable), or annual Campus Fund of THB 60,500
- Harrow: THB 225,000 non-refundable admission fee + THB 200,000 deposit
- ISB: THB 260,000 non-refundable registration
- Paying any required refundable deposit
These fees are paid before your child begins school. Budget for them alongside your relocation costs. They are commonly wired by international bank transfer; confirm banking details directly with the school's finance team.
Stage 5: Enrolment Documentation and Visa
Enrolment Documents
Once the place is secured and fees paid, the school will request final enrolment documents:
- Original or certified copy of birth certificate
- Medical forms / immunisation certificate (may require specific Thai or school format)
- Emergency contact information
- Any SEN/EHC plan documentation (if applicable)
Education Visa (Non-Immigrant ED)
Foreign children residing in Thailand to attend school require a Non-Immigrant ED (Education) Visa. The process:
- The school provides a letter of acceptance and relevant documentation
- Family applies at a Thai consulate/embassy in the child's home country, or converts status in-country at a local Immigration office
- The ED visa is typically issued for one year and extended annually, with the school providing attendance records to support each extension
- 80% attendance is required to maintain visa status — this is enforced
Most Bangkok international schools have dedicated admissions or visa support staff who guide families through the ED visa process. Do not attempt this without the school's guidance as requirements change.
Guardian Visa (Non-O)
One parent may reside in Thailand on a Non-Immigrant O (Guardian) Visa based on their child's ED visa enrolment. Requirements typically include:
- Proof of funds in a Thai bank account (commonly in the region of THB 400,000–500,000, though the exact threshold varies by consulate and by year — verify the current figure before relying on it)
- One Guardian visa per enrolled child
Families where one parent holds a Thai work permit (Non-Immigrant B) typically place children on dependent Non-O visas; in that case the ED visa is not needed.
Tips for Families Applying From Abroad
Start online. All major Bangkok schools have thorough websites, virtual tours, and online open day recordings. Attend an online session before committing to a trip to Bangkok.
Visit during a school day where possible. Most schools offer campus tours for prospective families. If you are making a reconnaissance trip to Bangkok, book tours in advance — they are popular.
Apply to multiple schools in parallel. Even if your first choice is NIST or Bangkok Patana, apply simultaneously to two or three schools. Paying multiple application fees (each THB 4,000–6,000) is a far smaller cost than arriving in Bangkok without a school place.
Give your child's current school adequate notice. Schools need time to complete the confidential reference. Applying in October and asking a school to turn around a reference within a week creates unnecessary difficulties.
Check the UCAS or home-country university implications of your school choice before committing. If you are likely to return to the UK mid-way through secondary, consider whether IGCSE continuity matters and which schools offer the most portable qualifications.
For further guidance, see our companion guides on international school fees, waiting lists, and university admissions from Bangkok.
How Global Investments Can Help
Global Investments works with families relocating to Bangkok and can help you align your school search with your property search from day one. Choosing the right neighbourhood is closely linked to school selection — Bangkok's traffic means that living close to your chosen school significantly affects daily quality of life. Our network includes contacts across the Bangkok expat community and we can connect you with local advisers who specialise in supporting families through the full relocation process. Contact us for an introductory conversation.
This guide is for general information only. School fees, accreditation status, and visa requirements change regularly. Always verify current information directly with schools and relevant Thai authorities.
Frequently asked questions
When should I apply to Bangkok international schools?
For an August 2027 start, apply in October or November 2026. The most competitive schools — particularly NIST and Bangkok Patana at key year groups — need even earlier engagement. NIST advises applications by mid-December for the following August start, but due to nationality quotas, places for British families may already be Wait Pool by that stage.
What documents are needed to apply to a Bangkok international school?
Standard documents include completed application form, copy of child's passport, recent school reports (two years recommended), confidential teacher or head teacher reference, immunisation records, and a passport photo. EAL assessment records are required for children whose first language is not English.
What is the CAT4 assessment used in Bangkok school admissions?
CAT4 (Cognitive Abilities Test, 4th Edition) is a widely used reasoning assessment that does not test curriculum knowledge. It assesses verbal, non-verbal, quantitative, and spatial reasoning. Many Bangkok international schools use it for Year 7 entry and above. It can be taken at the school or at a registered test centre.
Can I apply to Bangkok international schools before moving to Thailand?
Yes. Most schools accept applications from families who have not yet relocated. The CAT4 assessment can often be arranged remotely or scheduled to coincide with a visit to Bangkok. Online open days and virtual school tours are widely available. The entrance fee to secure a place is typically paid once you have accepted an offer, which can be done before arrival.
This guide is for general information only and does not constitute financial, legal or tax advice. Rules, fees and regulations change frequently; verify current requirements with a qualified adviser before acting.