CCTB will give you the 牛奶金 without any questions when you apply for. But once your file has been checked. CCTB will request the proof of your child who stay in Canada. Such as school report etc. If you cannot provide such documents. You will be in a big trouble. You need to return all the 牛奶金 plus interest, you will lost all your credit in Canada and your file will be checked every year. One of my friend have the same case couple years ago.