The British International School, Istanbul
Key Stats
Annual Fees: US$17K - US$45K
Curriculum: British · IGCSE · IB Diploma
Age Range: 2.5-18
Students: ~600
Location: Sarıyer (Zekeriyaköy), Istanbul
Updated April 2026
In Brief
The safest all-round choice for a British or internationally mobile family in Istanbul - small classes, triple accreditation, and a forest campus that no city-centre school can match. The Zekeriyaköy location is the trade-off: if you're based anywhere south of Maslak, the commute will dominate your morning.
BISI is the only school in Turkey to hold all three of CIS, COBIS, and MSA-CESS accreditations simultaneously, and that triple credential matters when a family might move mid-education. The school runs from age 2.5 through to Year 13 on a single forest campus near Belgrade Forest - small enough (around 600 students, capped classes of 12) that teachers know your child well before the end of the first term. Graduates have gone to Cambridge, LSE, Imperial, NYU, and UC Berkeley, and the school claims a 100% IB pass rate.
The daily reality is shaped by geography. Zekeriyaköy is genuinely remote - set inside the Belgrade Forest corridor, about 35 km north of the Bosphorus Bridge. If you live in Levent, Beşiktaş, or on the Asian side, you're looking at 45-60 minutes each way in a school minibus. Families who live in Sarıyer, Tarabya, or Büyükdere find it manageable. The campus makes the commute worth considering: a botanical garden, multiple outdoor sports pitches, and space that city-centre schools simply don't have.
The honest trade-off is cost against distance. Fees run from US$17K for half-day pre-school to over US$41K for Year 13 - plus a US$1,250 application fee and US$5,500 non-refundable registration. That's at or above what IICS and MEF charge for comparable year groups. If the forest setting and British continuity matter to your family, it earns that premium. If you're central Istanbul or self-funding, compare carefully before committing to the commute.
What parents value
- –The only school in Turkey triple-accredited by CIS, COBIS, and MSA-CESS - meaningful continuity for families who move frequently between international postings.
- –Class sizes capped at 12 across all year groups; at that size, teachers know exactly where each child is, and parents report visible individual attention rather than group-level feedback.
- –Forest campus near Belgrade Forest - botanical garden, outdoor sports, and space that's genuinely rare for Istanbul. Children arrive at a campus that doesn't feel like a converted office block.
Points of consideration
- –Zekeriyaköy is the furthest north of Istanbul's main international schools. Families in Levent, Şişli, or on the Asian side should work out the commute before applying - 40-55 minutes each way is realistic at school hours.
- –Non-refundable registration of US$5,500 is high; if you leave the city unexpectedly, that money is gone. Confirm the withdrawal and refund terms in writing before paying.
- –The school is smaller than IICS and MEF, which limits the breadth of senior electives and team sports at scale. Ask specifically about IB subject options at Diploma level and how many students typically take your child's likely combination.
Annual Fees
| Year Group | Age | USDTotal Annual Fee |
|---|---|---|
| Pre-School (Half Day) | 3 | NaN |
| Pre-School (Full Day) | 3 | NaN |
| Reception | 4 | NaN |
| Primary | 5 | NaN |
| Secondary Y7-10 | 12 | NaN |
| Secondary Y11-12 | 15 | NaN |
| Secondary Y13 | 17 | NaN |
Fees converted from TRY. For the most up to date and accurate figures please double check with the school.
Additional Fees
| Fee | Amount |
|---|---|
| Application Fee (non-refundable) | NaN |
| Registration Fee (non-refundable) | NaN |
Academic Results
Academic results have not been made publicly available by this school.
Extra Curriculars
Contact the school for details on co-curricular activities and facilities. Ask what a normal week looks like outside lessons for your child's age group.
Inspections & Accreditations
Inspection
- Triple-accredited: CIS (Council of International Schools), COBIS (Council of British International Schools), and MSA-CESS.
- Only school in Turkey to hold all three accreditations simultaneously.
Accreditations
- CIS
- COBIS
- MSA-CESS
Memberships
- COBIS
Student Body
Around 600 students from 55+ nationalities attend BISI, with a mix of diplomatic, corporate, and long-term resident families. The relatively small roll means the community is tight-knit; families who've been here describe knowing most parents by name within a year.
Leadership
School leadership
Contact the school for details.