To teach English in a language school in UK you will need a degree and a CELTA - absolutely no language school would employ you without a CELTA, even if you have other education qualifications, such as a BEd or PGCE. We see PGCE etc as a bonus but we wouldn't even interview without a CELTA. There's no point. Education degrees and PGCEs are, after all, usually geared towards teaching children, and not usually connected to language-learning (unless your PGCE is in French or something). Since teaching in a language school requires (a) knowledge of language and (b) pedagogy skills more pertinent to (fee-paying) adults, a CELTA gives a better impression of your capabilities. Obviously, it's just an entry-level qualification, so you have to do a lot of learning on the job, but your performance on CELTA will usually give a good indication of your potential. To an extent, PGCE skills are transferable to the adult sphere (the basic principles of education are not unduly complex, after all), but in my experience PGCE-qualified teachers are by no means the best language teachers. Some are excellent, of course; but many others simply can't make the transition to a language school environment effectively. (There are also hugely different demands--discipline being not the least of these--between teaching a group of 30 teenagers in a comprehensive school and teaching a group of 12 foreign university students in a private language school).
This is the case in the UK, where I have most experience. Asia and South America tend to be less rigorous, although some countries are now tightening up as the teaching market is getting saturated - you would now be unlikely to find a good job in Thailand, for example, without a relevant qualification or well-placed contacts. Of the Asian countries, Japan is certainly the most rigorous when it comes to employing people. Jobs with international firms (International House, British council etc) will require a CELTA.
I have worked with one excellent teacher who only had celta (no degree) but she really is the exception. Usually you would need a degree to get a job in a language school. Most relevant degrees would be languages or linguistics --- I personally would preference these to English or education, although those are useful too.
It is worth adding that most people with a CELTA do not go on to teach full-time for the rest of their lives. Many of them find they don't take to the profession, or the profession doesn't take to them. It really is quite a basic qualification, which, like all qualifications, is a starting-point for a career, not a goal in itself. Be that as it may, it is indispensable for a career teaching English for adults, and if you are considering a stint in TEFL it is well worth the relatively modest investment in time and money that it requires.
Posted from TSR Mobile