Sounds like you are going to spend the next couple of days making a lot of phone calls. My guess is that you did not address your invitations correctly, or you would not have the extra people invited.
Most people do away from the inner envelope and then address to Person and Family, which just means they can invite as much family as they want. The inner envelope is to indicate exactly who is invited to the wedding in the family.
If you want to avoid the calls, just estimate how many people are associated with the 52 invitations and give that count to the caterer. You may be paying for more food (which you could ask if the caterer will donate extras to shelters or possibly will box up the leftovers to freeze. |