I didn't think this would an issue I would have but I have a bunch of people that didn't RSVP, and it's past our RSVP date.
One response I got when I asked was, we don't know yet because money is tight. I said, okay cool, just let me know very soon. I felt bad asking though.
This is very awkward to go around asking for RSVPS. What's the best way to handle it?
Re: How should I ask for those who haven't RSVP'd?
Allyou can do is call people up and say "hi so and so, just wanted to follow up with you and find out if you can make it to the wedding. Our caterer needs our final numbers by XX date. Please let me know before that."
If if you don't get a response, leave another message and tell them "hey so and so, we haven't heard back from you on whether you're coming to the wedding. The final numbers have been submitted to the caterer and we assumed you were not coming. We will miss you!"
Unless you're asking for RSVPs super early, the awkwardness should be on them for not responding.
Note that your RSVP date shouldn't have been more than a couple of weeks before your wedding. If you set yours too early, you should wait a while before starting to call on people.
If they don't give you a yes or no answer right there (ie money is tight so they don't know, they don't know their work schedule etc etc) just say
'Of course, I understand. Our hard deadline is Friday the X so if you can just let me know before then or else I can mark you down as a no. I hope you'll be able to join us. Give my best to Susan.'
Basically you need to let them know that if they don't give you a yes by X date, they are a no.