If you want to teach in Japan or Taiwan then you will require a university degree in order to get a visa. In Japan, depending on what passport you hold, you can get a working holiday visa up until the age of 30 regardless of whether you have a degree or not.
The positive feedback we get from our ICAL graduates who have found employment in language schools not only in Asia but all over the world, in both the private and public sector, confirms that our Certificate is extremely well accepted. Specifically we have many graduates who have found employment in Japan thanks to their ICAL Certificate and related papers.
There is a thread on this in the ICAL Student Forum at http://www.icalweb.com/forums
We also cooperate with major recruitment agencies in Asia who ask us for our ICAL graduates on a regular basis as they know they can easily place them. Not only reputable placement agencies are happy to recruit our certified teachers but we also have schools from all over the world - from Turkey to Indonesia - that regularly contact us looking for well trained TEFL/TEFL teachers to employ.
We believe all this speaks volumes about the standing the ICAL certificate has in the ELT industry. However since rrequirements vary from school to school and country to country, if you are concerned about the validity of the certificate, then the only sure way to find out is to talk to the school(s) where you'd like to work. They will have their own preferences.