Other Addressing Etiquette

Unmarried Couples
Address the envelope to a couple living together but not married with each name on a separate line, flush left, alphabetically, with no and between the names.

Children and Teens
Girls are Miss from birth until 21, when they may wish to be become Ms. However, girls’ envelopes are generally addressed by name only until they become teenagers, when Miss is used more often.
Boys are correctly (but not necessarily) addressed as Master until age eight, when that term is dropped in favor of the given name and no title. He becomes Mr. at age 18.

Messrs.
Abbreviated from the French for Misters (Messieurs), Messrs. applies only to brothers, not to other male family members like uncles or fathers. If the envelope is going to all of the brothers in the family, it is addressed to The Messrs. Smith. If it is going to two of the three brothers in the family, for example, it is addressed to The Messrs. Lawrence and David Smith. The same rule applies to Misses.

Esquire
Originally, Esquire was the title applied to a knight’s eldest son or to the younger male members of a noble house whose hereditary title was borne only by the eldest male heir.
The title is seldom used today and only if the person being addressed is a lawyer, male or female. It follows the person’s name and is usually abbreviated as Esq. It can also be written out in full in the address. Do not use a prefix (Mr., Mrs., and so forth) when Esq. is being used after the name. When writing to a lawyer and spouse, drop the Esq. and address the letter to Mr. and Mrs. John Smith.

Addressing Officials
The proper forms for addressing various officials follow. The honorifics, Mrs. or Ms., may be substituted for Mr. where appropriate. If the official is a woman, give her husband’s full name: Elizabeth Smith and Mr. Harold Smith. If the wife of the official uses her maiden name, use that instead of Mrs. Smith.