Wedding Invitation Etiquette

Address them like this:

Mr. John Doe and Guest
…

Mr. and Mrs John Doe and Family
…
References :

By Mrs♥B2b on Sep 29, 2009

Send each guest his or her own invitation, to their own homes.

Every single person who comes to your wedding is *your* guest, even if you only invite them to please someone else. All your guests have a right to be treated equally: to be invited in their own right, by name. You can find out the name and address of your guests’ significant others by phoning them and asking.

If you have not yet ordered your invitations, consider having them printed with a "write-in" line. The custom of specifying invitees on the inner envelope is an alternative to this more traditional (i.e. older) style where the invitation reads

"Mr and Mrs John Goodhost
request the pleasure of the company of

at the wedding of &tc …"

With this form you can just put the legal post-office approved form of address on the out envelope and let the invitation speak for itself regarding who is invited. And, lest you should think this is a declassé modern alternative, you can look up the last several invitations to Royal weddings and see examples of a "write-in" line in use.
References :

By aspasia on Sep 29, 2009

I am addressing the outer envelopes as the person who is invited such as:

Mr. and Mrs. John Doe
Mr. John Doe & Ms. Jane Smith
Mr. and Mrs. John Doe and Children
Mr. and Mrs. John Doe and Mr. Thomas Doe

Then on my RSVP cards I state how many seats are reserved for them so for people who are just one person but will have a guest then they know they had an additional seat then if I want only certain people invited with other people then I will write it specifically on the outer envelope.
References :

By Philly K on Sep 29, 2009

Address the envelope with the formality of a "typical" outer envelope but the inclusiveness of the inner:

Mr and Mrs Jonathan Doe

Mr and Mrs Jonathan Doe
Sally, Suzanne, and Tomas Doe (Children are addressed oldest down)
Address

Mr Jonathan Doe and Ms Jane Smith (Invite person with named guest)
Address

Mr Jonathan Doe and Guest
Address
(Inviting Male, unknown Guest)

Ms Jane Smith and Escort or Guest
Address
(Inviting Female, unknown Guest)

Ms Jane Smith
Mr Jonathan Doe
Address
(Couple living together)

Though of course you want to name the guests when you can (dating couples, etc), it’s not always possible. Two of my future BIL’s were not dating anybody ‘exclusively’ when we sent out the invitations. Of course, they were going to get a guest, and it was going to be of their choosing. I wasn’t about to say, ‘Timmy and Sarah or Kristy or Anne.’ However it would be in your best interest to call and get names of guests who will be attending that you know – Stephen’s longtime girlfriend Lisa-what’s-her-name. Simply call Stephen (or his parents) and ask for the proper spelling of Lisa’s name. No need to volunteer that you don’t know the name.

Also, avoid addressing them to "…and family." This leaves the interpretation to the invitees, and they may consider Sally’s boyfriend Tommy "family" when you obviously didn’t. (On that note, any child invited with their own guest should get their own invitation. Any person over 18 should get their own invite, even if they still live with their parents.)
References :

By Just tryin' to help on Sep 29, 2009

We’re not using an inner envelope either, but our invites are quite unconventional (think 3D puzzle). After days of researching wedding etiquette, my fiance and I decided to address our invites as you normally would (i.e. "Mr & Mrs John Jones" or "John and Jane Jones" depending on formality of your wedding) and designate who the guests are on pre-printed RSVP cards using the rules for inner envelopes.

So, instead of the following (where they write their own name in):
M__________________
__Accepts __Declines

We have this (our wedding is quite informal):
John & Jane Jones
Johnny Jr. & Baby Jones
__Accepts __Declines

Or, if you want more formal:
Mr. & Mrs John Jones & Children
__Accepts __Declines

We are hoping this also stops my aunt from adding "+7" to yet another wedding RSVP. I’m not sure how successful we will be.
References :

By CGW on Sep 29, 2009

I have read that you are NEVER supposed to put "and Guest" on any piece of mail. Does someone named Guest live at your house? That would be a rather unusual name! I have heard postal workers joke about it or were confused by it? I couldn’t really tell.

Instead, do what etiquette dictates and what I did. Fill out the RSVP by putting their name on the line like this (If you want to be more formal, put Mr. or Ms. in front of their name and find out and write in their guest’s name):

John Doe and _______________
_____Graciously Accepts _____Regretfully Declines

If you want to invite children, put their names on the RSVP line as well. I did mine like this:
John, Jane, Jack, and Mary Doe
_____Graciously Accepts _____Regretfully Declines

This way you indicate exactly who is invited.
By adding "and ___________" you implicate a guest can come as well.

Then you would just address the envelope to the people you know are coming (i.e. just to John Doe and not to Guest). You should address envelopes to the parents in the family invited and just include children’s names on RSVPs. Sometimes kids will take any piece of mail with their name on it and parents will never get the invitation!

Good luck & Congrats!
References :
bride to be 7-11-09

Here’s some advice from The Knot (one of the top wedding websites out there and definitely an expert you can trust) on the subject of addressing invitation envelopes:
http://wedding.theknot.com/wedding-planning/wedding-invitations/articles/addressing-wedding-invitations.aspx

By Gillian on Sep 29, 2009