At my ds's school (he is in Prep) the rules are that if you want to give out invites then you have to give invites to the whole class (which is essentially 2 classes of 13, so 26 kids). Then they will go home in the kids school bags. But if you want to invite only a few children you need to do that by handing out the invitations individually (basically that means parent to parent), but some of the kids go to before or after school care and I know the Mum's, but not the Dad's or Grandparents, etc. So, basically going by the hand it directly method I think it could take me a week to guarentee that I give out the invites to specific kids. We have a class list of contact details but only got it at the end of Term 1 and some parents don't have their contact details listed.
So, is this a common rule, that if you want to invite the kids it's a 'everyone' or 'no-one' rule for giving out invites? Does it just get easier as the kids progress through school as you know more parents & their contact details? We don't have to worry too much as our ds's Birthday isn't til January next year, but the thought of having 26 6 year olds is scaring me already (more from a financial perspective & the space perspective than anything -- he doesn't need 26 presents!!).