For most parties, we recommend sending out invites at least 3 weeks prior to your party date. This will give your guests time to RSVP and make any necessary arrangements to attend. This also allows you to move on to the next party project like party decor!🎈🎈
If your party is a little more fancy or formal (like a wedding) we recommend sending out invitations between 3-5 weeks. If you've already sent out save-the-dates then go ahead and send out wedding invitations at the 3-week mark since most guests would have your wedding date saved in their calendar already.
Basically, don't wait until the last minute. Factor in any travel arrangements, food and drink budget, and anything else you would need to know in advance and then plan accordingly.