AIBU to not let these children come to my DDs party?

[Caravanoflove]

DD has her 7th birthday coming up, I've invited about half the class to her party. Due to the type of party I have to confirm and pay for exact numbers in advance. I asked if people could rsvp by yesterday and added a note to the invite that I had to confirm numbers by this date.
Only half have replied. There's still a good number coming, enough for a nice party. Would I be unreasonable to not chase the non responders and if they do respond say sorry, tough (but in a nice way).
My worry is this will piss people off, I do know a lot of the mums to socialise with, and worry it will mean my dd will be excluded from future parties.
What would you think if you responded late to an invite to be told, sorry, too late?!

They may have forgotten with everything that's going on atm for xmas.
I would and have sent reminders to those who haven't responded.
It's the way it is unfortunately. However, it's only for a few years they soon grow out of parties.
Reming those on your list at pick up or drop off.

I'd just do a text to the one's who haven't RSVP'd saying something along lines of sorry you cant make the party, it would have been lovely to have you there.

YNBU to not chase and just say tough (nicely!). But the point of a party (other than to have a good time!) is to create strong networks. So missing the opportunity to chase after and build those networks a little is a bit of a waste.

But I'm quite lazy about things like this so I would probably go the way some others have suggested of chasing anyone in particular (your good friends, DD's good friends, etc.) and leave the others.

I've been at the receiving end of this! There was no last date to RSVP by. Even so I replied 5 days before the party which I knew was too late. I genuinely couldn't confirm any sooner & knew I was risking it. The mum replied saying they'd confirmed numbers and were unable to add any more. I was totally ok with it. But mainly because I know this mum & she's really sweet. I was able to believe her at face value & be totally ok with it. When I met her next time she was so apologetic, but honestly it took me 2 minutes to even remember what she was being sorry for.

Thanks everyone, I've chased a few (all had got the invite and said yes). I'll decide about the others tomorrow as they are mums I don't know that well and not that invested in maintain friendships.