Charter International School

Charter International School opened in 2003 on Chaloem Phrakiat Rama 9 Road in Prawet, east Bangkok. It is a Thai family-owned school founded by the Thienprasiddhi family, who also run the Plengprasiddhi kindergartens. The main administrative building, completed in 2006, is modelled on Baan Si Chom Phu, the family's historic pink house on Silom Road. It is a small school with a close community and students of many nationalities.

Charter follows the English National Curriculum, adapted for an international setting, from Nursery through Year 13. Students sit Cambridge Checkpoint in Year 9, IGCSEs in Years 10 and 11 and A Levels in Years 12 and 13. The school is a Cambridge examination centre and has a joint CIS and WASC accreditation. English Language Support is part of the programme, and Thai nationals are also tested in Thai at entry from Year 7.

Facilities include two indoor basketball courts, a gymnastics room, grass sports fields, a half-Olympic pool with a separate Early Years pool, a 500-seat theatre, primary and secondary libraries, science labs, art and design rooms, music practice rooms and a dance studio. Fees for 2026/27 are charged per term and include lunch, snacks and after-school activities. They come to THB 510,000 a year for Years 1 to 6, THB 582,000 for Years 7 to 9 and THB 612,000 for Years 10 to 13. New students pay a one-off enrolment fee of THB 100,000, and paying for the full year up front earns a 5% discount.