I personally don’t believe in language certifications because I think that it’s only a matter of preparation. If you spent a lot of time preparing for these tests then you’re going to get a good result. I say this because I’ve sat in on an interview wherein this person was being asked questions in English, and she had to answer in English too, of course. I wouldn’t say that her English is bad, but I wouldn’t say it’s remarkable either (I’m not saying I have perfect English, because I sure don’t). However, I recently found out she got an 8.0 IELTS score, and a 980 TOEIC score. Pretty impressive. She spent a year preparing for those exams, which I guess is one of the main reasons why she scored well.