Applying for teaching position in international high school

Hi everybody, I'm pretty new here so if there's any problems with my post, sorry in advance.
I'm Vietnamese, currently in UK but for the next 3 years, I need to be back in HCM city so I'm considering applying for a teaching position here. What I have in mind is not English teaching one but a subject high school teaching, similar to A-level program. I have a look around and realize that all of the good school require some teaching qualification and seems to prefer foreign teachers. I don't have any teaching qualification but I have BA and Mphil degree from Cambridge University in Economics, have done lots of teaching at undergraduate level in Math and economics.

Can anybody here give me some idea of how reasonable a chance of me getting a job offer (I'm talking about those with good standing like Australian International School, AGC or ISHCMC?

Thank you very much

The degree is more important that the teaching cert to get a job at any of the International schools. BUT I'm pretty sure most of them will want some kind of teaching cert to go with it.
Hopefully some of the teachers on here will be able to clarify that further for you.
Get in touch with some of the schools directly and ask them what they require most are petty forthcoming with that kind of information :-)

Yeah! Take that from the Expert.