Guests wanting to attend last minute

If it's after the RSVP date and you don't want to rearrange your plans, you can always say something along the lines of, "I'm so sorry! We didn't hear from you by the RSVP deadline, so we marked you down as not attending. We already gave our final counts to our venue and caterer, and are not able to make changes." However, if the RSVP date passes and there are people you haven't heard from, I would definitely reach out to them to remind them to RSVP before assuming that they're not attending.

It looks like your wedding is in October. Did you send your invitations already?

That’s why you spend the buffer week following the rsvp due date tracking down anyone who didn’t send theirs in, starting the evening of the due date. If someone changes their mind and shows up past that point, they will not have a place card and it makes them look uncouth, not you. Many venues require you rent security which will turn away anyone who is not invited or rsvp’ed no and changed their mind, but they have to be informed of the list. It’s not something you need to do deal with on the wedding day.

View Quoted Comment No not yet thankfully, I’m just a huge planner and I tend to stress over stuff like this so I wanted to get ahead of the game!

View Quoted Comment Thank you! That is very good to know

View Quoted Comment That makes sense! Always a smart idea to be prepared. Hopefully it won't end up being an issue!

Set your RSVP deadline about a week before your vendors need final headcounts, and then you can use that week to track down anyone who didn't RSVP. If they say no or you can't get in contact, then mark them as a "no." Some planners/ venues will recommend having an "overflow" table in the event something like that happens, there's a miscount, etc. Then you're at least prepared in the event there's an issue.

You'll more than likely have offsetting guests who RSVP Yes, but then can't make it at the last minute, so don't forget to account for that as well. They will likely cancel each other out.