Last year, I think we were instructed by Bromley to contact Bexley admissions and ask for our ds to be put on the waiting list for Chis and Sid. I did this by email and they responded, confirming receipt on my email (They were very efficient and quick to respond). I also asked them (Bexley) at the same time, how far first offers had come - this gave me some idea about how near we were. Happily, we were offered a place at Chis and Sid in the next round of offers.
Check your admissions letter for details concerning putting your child on a waiting list. This may vary depending whether the school is in your borough or not.
How do we know the date when they start offering places? Or the second round? Or when do we know what position our children are on the waiting list?
Did you ask the schools or Bexley Admissions?