The style and level of formality you use in addressing all of your correspondence should directly reflect the style and level of formality of your wedding, not your relationship with the guests. A casual wedding with a buffet style dinner would probably best be reflected by the informal choices. An elegant, formal sit down dinner would best be reflected with formally written invitations. Remember to have the style of the invites and other stationery reflect the style of the wedding as well.
Suggested ways to address invitations:
Outer envelopes:
Single recipient:
Mr. John Smith
123 Circle Road
City, State 12345
Married couple, Traditional
Mr. and Mrs. John Smith
123 Circle Road
City, State 12345
Married couple, Modern
John and Jane Smith
123 Circle Road
City, State 12345
Couple with different last names living together
Ms Jane Smith
Doctor David Jones
123 Circle Road
City, State 12345
Children
Children over 12 may receive their own invitations. They may also be added under the parents name on the envelope.
Mr. and Mrs. John Smith
Jessica Smith
123 Circle Road
City, State 12345
If you are using an inner envelope as well as an outer one, you would not put the children’s names on the outer envelope.
Inner envelopes:
Inner envelopes are more informally written and do not include addresses. Traditionally the names would be written the same as above for formal versions. The informal versions would be written as follows. Also included are formal versions of the less traditional scenarios.
Single recipient, informal
Uncle John
or
Jane
Married couple, informal
John and Jane
Couple with different names living together, formal
Lt. Smith and Ms. Jones
Couple with different names living together, informal
John and Jane
A family, formal
Mr. and Mrs. Smith
Jessica and David
A family, informal
John, Jane, Jessica and David
If you will only be using an outer envelope, children should be included there.