The CELTA is a common requirement for those entering the field of English language teaching. Because it is recognized internationally, it is a particularly popular credential among people who wish to travel and teach English around the world (see TEFL for an extended discussion of travel-teaching). However, it is also held by people who intend to teach only in the country where they trained, and do not intend to travel.
The full-time CELTA course runs for four weeks; it can also be taken part-time over several months. CELTA courses are run by many different institutions, while the courses are validated and certificates are issued by the University of Cambridge Local Examinations Syndicate (UCLES).
The CELTA is awarded upon passing the course, which includes at least six hours of supervised teaching practice to real English language students, at two different levels. The course grade is determined primarily by the performance of the teacher in this teaching practice; there are also a number of written assignments due throughout the course, which are graded on a pass/fail basis only. The grades awarded are pass, B and A. As of 2000, worldwide five percent of trainees withdrew before completing the course, three percent failed, 63% received a pass, 25% received a grade of B, and four percent received a grade of A.
The full-time four-week course is very intensive, and students taking it must be prepared to dedicate all their waking hours to it for the duration. Even the part-time version of the course can take up more time than a full-time job for many students, especially those with no teaching background.
Each year around 900 CELTA courses are run by around 280 centres, primarily language schools, in 54 countries, producing over 10,000 graduates. Each course is audited by an external assessor.
The current Cambridge CELTA replaced the RSA/Cambridge CELTA in 2001. In 1996, RSA/Cambridge CELTA replaced the RSA/Cambridge CTEFLA (the Certificate in Teaching English as a Foreign Language to Adults)—this was jointly administered by the RSA and UCLES. The RSA/Cambridge CTEFLA replaced the RSA Certificate in 1985.
A less common qualification from Cambridge Assessment is the CELTYL—the Certificate in English Language Teaching to Young Learners. Like the CELTA, it runs as a full-time course for four weeks. It is equal in status, having the same number of hours of instruction, teaching observation, and supervised teaching practice, but focuses on the teaching of children. Candidates who have already been awarded a CELTA can take a "YL extension course" in two weeks, which adds a qualification in teaching young learners to their existing qualification in teaching adults.
The DELTA is the diploma in ELT offered by the same organisation that offers the CELTA and the CELTYL, i.e., Cambridge Assessment. It can be taken as a follow-up to the CELTA by those seeking further qualifications in the field.
In order to meet the UK government's criteria for teachers of ESOL in the Learning and Skills Sector (that is, adult education) in England and Wales, holders of CELTA need to undertake an additional qualification, known as CELTA module 2.