Last year 6 months before her birthday (15) I told my daughter if she wanted a party we would give her one. She was like ok mom, not a yes, not a no, not really interested. So I didn't plan one. The day before her birthday I kid you not she asked who she could invite to the party. So I had to tell her sorry no party we had already spent the birthday money on gifts for her and didn't plan for a party. So this year I told her just a couple weeks ago that for her birthday (in April) she can either have a party or get something real nice for her birthday. She chose the something real nice.
Out here in elementary school they tell parents that if they are going to send invitations with their kids to pass out at school they have to invite all the kids in the classroom. My daughter gets several invites each year.