Written correspondence carries an etiquette code that affords individuals and their names respect. When addressing a thank-you note to man and woman together, find out if they are married, if they have different last names and if they hold specialised degrees such as Medical Doctor. Formal introductions are always a safe bet, but they are required for wedding invitations, business letters and thank you cards addressed to a couple with whom you are not closely acquainted.
Write their honorific titles first. For example, "Mr. and Mrs."
Write the first name of the man, John for example. So the address would now look like: Mr. and Mrs. John.
Write the couple's last name, Jones for example. The final form, in proper written etiquette, reads: Mr. and Mrs. John Jones. In cases where the last name is shared, the man's first name should always accompany his last name.
Write Drs. to address the fact that they are doctors.
Write the woman's first name after Drs. The address reads: Drs. Anne.
Write the man's first and last name next to each other. Following the same example, the address would read Drs. Anne and Chris Smith. To simplify an address to identically degreed spouses, you may choose "The Doctors Smith," using the last name from the previous example.
Write the woman's full name, first and last.
Write the man's full name, first and last, after the woman's, for example: Jane Johnson and Christopher Jones.
Write the woman's first name, the man's first and last name if the couple is married but the woman has retained her maiden name. Her last name will not show in this case. Use this form of address only when you know the couple is married. For example: Jane and Christopher Jones.
Write the woman's first name.
Write the man's first name.
Leave out last names entirely.