International House has been a promoter of teacher training since its foundation in 1953. It was the first to introduce the "Teachers of English as a Foreign Language" (TEFL) certificate back in the 1960s when this sector was still in its early stages of development. Its name was then changed to CELTA Certificate of English Language Teaching to Adults and DELTA Diploma of English Language Teaching to Adults, and its management and coordination were taken over by Cambridge ESOL.

Our teachers and language consultants are all native speakers or bilingual speakers holding Celta and/or Delta certificates, the IH Certificate or a similar qualification to teach languages to foreigners. Some teachers also have a suitable professional background to teach executive and special purpose courses.