It has three campuses serving the educational needs of the international community in central London and surrounding areas.

In 1982 the school moved to Eccleston Square near Victoria Station and by 1985 a secondary section was added, and the IB Diploma Programme was eventually adopted.

[2] The group made complaints that Cognita had "no serious interest in maximising the educational experience of ... children if it impacts on their bottom line".

[5] Cognita provided funding to open an IB Diploma Programme Centre on Conway Street for Grades 11 and 12 and this operates as an annexe to the main campus on Portland Place.

The Conway Street building opened in August 2007 and students from the Middle School in Hampstead (grades 6, 7 and 8) joined the Westminster campus.

In August 2012 Cognita acquired the Charteris Sports Centre in London as a facility for Southbank International School which is let out to the community in non-school time.

[9] In March 2014, William Vahey, a teacher who had worked at the school for several years, was found dead.

[10][11] He had been jailed for child sex offences in California in 1969 and it is thought he had abused over 50 students at Southbank.