Kid restrictions by age?

We invited age 21 and up, which is the norm, in our family/social circle, along with formal/evening weddings, that last until 10 PM to after midnight.

I have 18 nieces and nephews, one of my aunts/uncles has 20+ kids, my husband's parents each had 8+ siblings on each side, so that me of cousins with ages all over the place. It was difficult to tell them not to bring ALL the kids. They decidedly among convenience to find sitters for some and leave siblings at home. I love them all and am close to them all, as is my husband. We didn't have an age limit, but I understand your dilemma. My cousin (who has the exact same cousins as me as her dad is the brother of the one with the thousands of kids) decided last year at her wedding that NO kids were allowed, except those in the wedding party, ie: flower girls, ring barer....I had never heard of an only adult wedding, ESPECIALLY in my enormous family. I think it is ok to say ages 5 or 8 and up. If the parents end up having to find a sitter for the younger siblings, that isn't on you. It is your choice. I'm sure that giving them enough notice won't be an issue. Why should you have to accommodate infants and toddlers? Don't feel guilty. I'm just learning this myself. I've even to several weddings where I couldn't hear the speeches or vows because of babies. There shouldn't be any fall out from it, especially if this is made clear of n advance for arrangements to be made and discussions to be had. I know that with my cousin last year, some of the family members got together and had a slumber party for the kids(the wedding venue was a 6hour+drive from home) so the parents wouldn't be back til the next evening. They built forts, went into the backyard and made s'mores, went swimming, had sooo much fun together. The kids had so much fun as did thie parents. It was New for the whole family, since this was the first wedding of its kind among us. I hope this helps.

I'd do 18 and older. You may split families up. I don't think someone with a four year old will feel like their kids are more obnoxious than a nine year old, and probably won't understand why you chose the threshold you did.