Hi Heidi

Depends greatly on where you are planning to teach. Europe, for example, tends to demand some form of credible (credible in both course structure/content/classroom experience and accreditation) certification (Cambridge, Trinity or equivalent) and I would advise strongly against an on-line course.

There are places such as China, Thailand, and Korea etc where you will probably have no problem finding work with any piece of paper that says you have done some form of teacher training course.

At the end of the day it probably doesn’t matter to your students what course you have done, just that you can teach. You are much more likely to be able to teach at the end of the course if you have actually had some hands-on experience in the classroom… this is very hard to do on-line!

CELTA and Trinity Cert TESOL are expensive… but there are worthwhile alternatives – check out TEFL International’s PELT course. It puts huge emphasis on classroom experience and is considerable cheaper than your average Cambridge or Trinity course…

Hope this provides insight!