Alphabetizing Place Cards

If your venue is requesting this, I'd first make sure that they're okay with two people being on one place card! Giving each person their own would also make it easier on you when it comes to alphabetical order.

I also agree with Grace. If it's fine to have two on one card, just go by the last name of the first person listed.

Are they escort cards (displayed somewhere for guests to grab and take to their seats) or place cards (already at the seat, guests walk around the tables to find their name)? If place cards, I'd just do one per person since two people can't occupy one seat. If escort cards, alphabetize by the last name of the first person listed (personally, I'd list the person I know best first).

One per person because they can not both take up one seat. John Doe would be listed under D and Mary Smith would be listed under S. Guests in general are much more intelligent than they are given credit for. Escort cards are a vital way for waitstaff to tell who gets what meal and that doesn’t work when you have two names on one card. Also, there is no reason to pick the chair for everyone, just assign them to a table.

I would also do separate cards for different names.