To some couples, omitting wives’ first names feels too old-fashioned; including the first names of both husband and wife after their titles is appropriate. The house number, even though it is less than 20, can be written as a numeral for a less-formal feeling. And in keeping with a more personal style, the couple are addressed by their first names on the inner envelope.
Different Last Names
When a husband and wife have different last names, the wife’s name is traditionally written first. Connecting the couple’s names by the word “and” implies marriage. For an unmarried couple that lives together, names should be written on separate lines without the word “and.” On the inner envelope, both are addressed by their titles and respective last names.