I work for an online company teaching English to Chinese students and my boss messaged me to say, have I got tefl certification! I didn’t have one at the time and apparently it is regulation to have one. So I scaled the internet and was overwhelmed by how many companies there were offering online tefl courses. I saw them really cheap groupon courses but I’ve heard so many bad things about them, and actually my boss said said they wouldn’t accept them certificates anyway, so I dodged a bullet there. I recommend WTI, their course is easy to navigate through, with great tutor support.