Guide to Writing Men's Names with Suffixes

The Basics

• “Mr.” is the default social title for a man.
• Formally, boys are called “Master” until about age six or seven, then have no title until age sixteen to eighteen, when they assume “Mr.”
• The plural “The Messrs” is used to address two brothers at the same address and most often used on the inner envelope of a wedding invitation

Who is a Senior, a Junior or The Third?

• A man with the same name as his father uses “Jr.” after his name as long as his father is alive. His father may use the suffix “Sr.” for “senior.” The son may either drop the suffix after his father’s death or, if he prefers, retain it so that he won’t be confused with his late father.
• When a man is named after his father who is a “Jr.,” he is called “the third,” once written with either the numeric 3rd or the Roman numeral III, but now the latter is used almost exclusively.
• A man named after his grandfather, uncle, or cousin uses the suffix II, “the second.”
• In writing, a comma is used to separate the surname and the suffixes Jr. and Sr., though the trend is now toward dropping the comma. Junior, when spelled out, is written with a lower case j.
• No punctuation is used when a name has a numeral suffix: Robert Conner III
• The wife a man who uses a suffix, uses the same suffix after her name: Mrs. John M. Baxter, Jr.