These guidelines are based on strict formal etiquette. If your announcement or invitation is less formal, it may be acceptable to deviate from these rules.
Envelopes may be addressed in your own handwriting or printed in black or dark-blue ink. The most formal invitation or announcement should be addressed in calligraphy. The recipient’s name and address appear on the front of the envelope. The sender’s return address traditionally appears centered on the back flap of the envelope. Usually no names appear with the return, but it is acceptable to show them.
Proper etiquette requires the recipient’s name to be preceded by a title. Address the envelope to “Mr. John Hancock” not “John Hancock”. When it is only to his wife, use “Mrs. John Hancock”. For a single woman, it’s “Miss Jane Williams”. Although the title “Ms.” should not appear on social stationery, it may be used on envelopes.
When the announcement or invitation is sent to a couple, it should be addressed to “Mr. and Mrs. John Hancock” rather than “John and Jane Hancock”. If the man’s name is followed by “Jr.”, “junior”, “III”, etc. the suffix also appears (e.g., “Mr. and Mrs. John Hancock, Jr.”). When a couple lives together but is not married, their names are written on separate lines alphabetically and the lines are not joined by “and”. When a wife uses her maiden name, address it to “Mr. John Hancock and Mrs. Jane Williams”.
In the special case where both husband and wife are doctors, you should write “The Doctors Hancock”. However, if they use different last names, you address the envelope to “Dr. John Hancock and Dr. Jane Williams”. Note that the husband’s name appears first. If the wife is a doctor and the husband is not, you send your invitation or announcement to “Mr. John Hancock and Dr. Jane Hancock”.
Abbreviations should not appear on the envelope except in the case of a title. “Mr.”, “Mrs.”, “Ms.”, “Dr.”, and “Jr.” are acceptable. Symbols such as the ampersand should not be used in place of the actual words (e.g., “&” for “and”). The recipient’s address and return address should be spelled out wherever possible. Road numbers, apartment numbers, and zip codes are written in their numeric form. However, the state and road suffixes such as “Street”, “Boulevard”, and “Drive” should not be abbreviated.