Halcyon London International School vs International School of London
🇬🇧 London · Side-by-side comparison on verifiable public data.
Both carry a public inspection verdict: Halcyon London International School is Independent Schools Inspectorate (ISI) "Met all standards (2024 routine, post-2023 framework)" and International School of London is Ofsted "Good" — a rare pairing where an official quality rating can be compared head-to-head. Both run the same curriculum (IB), so the differences come down to pathway detail, campus culture, and specific language/boarding arrangements rather than the curriculum framework itself. On cost, International School of London has the noticeably lower entry fee — a material difference for budget-conscious families. See the table below for the figures, and verify against each school's own published fees.
Key Facts
| Halcyon London International School | International School of London | |
|---|---|---|
| Curriculum | IB | IB |
| Ages | 11-18 | 3-18 |
| Languages of instruction | English | English |
| Annual fees | £41,040-£42,912/year incl. VAT (2026/27) | £24,630–£39,640/year (2026/2027, ages 3–17; figures incl. VAT where applicable) |
| Enrollment | 172 | — |
| Boarding | Day only | Day only |
| Inspection rating | Independent Schools Inspectorate (ISI): Met all standards (2024 routine, post-2023 framework) | Ofsted: Good |
| Accreditations | IB World School, ISI-inspected (DfE-regulated) | Council of International Schools (CIS), International Baccalaureate Organization (IBO) |
Strengths
- ✓IB Diploma average of 35 for the Class of 2025, above both UK and world averages, with recent perfect scores of 45
- ✓Continuous, focused IB pathway (MYP then DP) delivered by subject specialists with strong inquiry-led teaching
- ✓Small, intimate community (around 172 pupils) enabling close staff-pupil relationships and individual learning mentors
- ✓Genuinely international, largely bilingual student body with a strong inclusion, diversity and global-citizenship culture
- ✓Innovation-led ethos, including documented integration of artificial intelligence into the curriculum
- ✓Exceptional mother-tongue programme — 24 home languages taught as part of the curriculum, a genuine sector outlier
- ✓Strong bilingual outcomes — about half of leavers earn the bilingual IB Diploma, well above the IB world average
- ✓Full IB continuum (PYP, MYP, DP) under one provider, giving age-3-to-18 curricular coherence
- ✓Long pedigree and accreditation — founded 1972, CIS-accredited, authorised IB World School (code 000057)
- ✓Genuinely international and non-selective — 54 student nationalities across the IB programmes, open admissions
Trade-offs
- !Limited on-site sport and outdoor space; inspectors asked leaders to extend outdoor and physical-skills opportunities
- !Operates within a shared, leased central-London building rather than a self-contained campus
- !Young school (opened 2013) with a comparatively short track record
- !Small scale and secondary-only remit limit breadth of facilities, cohort size, and alumni network versus larger London internationals
- !Ofsted rating is 'Good', not 'Outstanding', so it is not in the top inspection band
- !High fees (up to £39,640/year) place it among the more expensive London options
- !Split-site model (Chiswick primary/middle, Ealing Diploma College) rather than a single campus
- !No British (A-level/GCSE) or American track for families wanting a non-IB pathway
Best Fit For
- • Internationally mobile families wanting an unbroken IB MYP-to-Diploma route in central London
- • Bilingual or multilingual students, including those targeting the IB bilingual diploma
- • Families who value a small, close-knit, innovation-led environment over a large traditional campus
- • Students who thrive on inquiry-based learning rather than a GCSE/A-level track
- • Internationally mobile families wanting a globally portable IB pathway
- • Multilingual households wanting their child's mother tongue actively maintained
- • Students who will sit the bilingual IB Diploma
- • Families seeking a non-selective school with a strong EAL on-ramp into English
University Placement
School-reported · not independently verified
School-reported, unverified: the Class of 2025 saw graduates progress to Russell Group universities and to specialist art, music and drama colleges in the UK and internationally.
School-reported, unverified: published higher-education destinations (2012–2025 dataset) include King's College London, UCL, Imperial College London, Warwick, Edinburgh, Manchester and Bristol in the UK, plus international destinations such as Bocconi, Sciences Po, McGill, University of Toronto, University of Chicago and Keio University.
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Frequently Asked Questions
Should I choose Halcyon London International School or International School of London?
Halcyon London International School is best for: Internationally mobile families wanting an unbroken IB MYP-to-Diploma route in central London. International School of London is best for: Internationally mobile families wanting a globally portable IB pathway. The right choice depends on target curriculum, budget, and family priorities — the two are not linearly comparable.
How do fees compare between Halcyon London International School and International School of London?
Halcyon London International School: £41,040-£42,912/year incl. VAT (2026/27). International School of London: £24,630–£39,640/year (2026/2027, ages 3–17; figures incl. VAT where applicable). Verify against each school's own published fees; some figures are sourced from third-party aggregators.
What curricula do Halcyon London International School and International School of London offer?
Halcyon London International School: IB. International School of London: IB. Halcyon London International School inspection: Independent Schools Inspectorate (ISI) "Met all standards (2024 routine, post-2023 framework)". International School of London inspection: Ofsted "Good".
Do Halcyon London International School or International School of London offer boarding?
Halcyon London International School: day school only. International School of London: day school only.
Questions parents ask
This comparison is BrightKey's independent assessment using verifiable public data only. University-placement figures are school-reported and not independently verified. BrightKey takes no payments from schools. Our method →