Applying for secondary schools when just moving to the area

[oxocube]

I am moving back to UK, to the North East of England and have 3 children, two in secondary and one in primary school. I know roughly where we want to live but we don't have an address yet as we are planning on living with my parents for the first month or so.

There is one high school in the area which seems significantly better than others in the LA and I would like my older kids to go there but I have no idea if there are actually places. What is the normal procedure (bearing in mind we won't arrive in the country until August!)? I have mailed the school to ask if they have vacancies and explained a little about our situation but do I also need to get in touch with the LA?

There is actually a high school about 100 mtrs from my parents' house but firstly, it has a much lower GCSE pass rate and secondly, I went there as a child and was very unhappy. Also, we really do hope to rent near the preferred school so this would become our nearest. I have also read somewhere on here about schools reserving a few places for children coming from either abroad or from another part of the country. Does anyone have any information about this please?

Thanks

Thanks so much Giddy for your comprehensive reply. I'm especially worried about my eldest who will be in the exam year (year 11) but has not followed the GCSE curriculum as my kids are currently in an IB school. He has an awful lot to catch up on. I'll look into applying through the LEA straight away. My ds will also probably be staying with my brother for some of the time as we will be seriously overcrowded at my parents and my brother lives about a mile away from our preferred school.

If it does come to appeal (and I know the school I would like is over-subscribed), would things like marital separation, emotional effects on the kids etc be taken into account? (All these things are true BTW so I'm not lying)

Very helpful Giddy. Many thanks again