Don't worry. 過來人,我係租屋既,租屋又用c6個名,The application is under my name (our rental contract is stamped but I did not take it with me) I took 水單as 地址證明,teacher checked my son's birth certificate where it has my c6's name. She also asked for a copy of my c6's HK ID (of course, I have a copy with me). Only 水、電、煤既單, 既地址證明. Other moms told me that sometimes in the future, someone may call for further address prove support ie stamped rental contract & land/rate tax...Good Luck