"Yours sincerely", "Yours faithfully," and "Yours truly"

The Quick Answer
Letters that start "Dear Sir," should end "Yours truly" (US convention) or "Yours faithfully" (UK convention).

Letters that start with a name (e.g., "Dear Mr. Jones"), should end "Sincerely yours" (US convention) or "Yours sincerely" (UK convention).
yours sincerely faithfully truly

"Yours sincerely" or "Yours faithfully"?

Writers are sometimes confused over whether to end a letter with Yours sincerely or Yours faithfully.

Even though there is a slight variation between British and American conventions, the rules are straightforward.

Use "Yours faithfully" () or "Yours truly" () for Unknown Recipients

If you do not know the name of the recipient (typically in business correspondence), use Yours faithfully if you're following UK convention and Yours truly if you're following US convention. (Letters that start with To whom it may concern fall into this category.)

Examples:
Dear Sir,

[blah, blah]

Yours faithfully,

Charles Windsor-Smyth
(Note: The use of Yours faithfully is growing increasingly popular in the US, but Yours truly is preferred.)
Dear Sir,

[blah, blah]

Yours truly,

Matt Brown

Use "Yours sincerely" () or "Sincerely yours" () for Known Recipients

If you know the name of the recipient (typically a colleague or close business associate), use Yours sincerely if you're following UK convention and Sincerely yours (or just Sincerely) if you're following US convention.

Examples:
Dear Mr. Jones,

[blah, blah]

Yours sincerely,

Charles Windsor-Smyth
Dear Mr. Jones,

[blah, blah]

Sincerely yours,

Matt Brown
(Note: The use of Sincerely (i.e., without Yours) is also acceptable in the US.)

With "Yours sincerely" and "Yours faithfully" Give Only the First Word a Capital Letter

Whatever you use, only capitalize the first word. For example:
  • Yours faithfully
  • Yours sincerely
  • Sincerely yours
  • Yours Sincerely

Follow "Yours sincerely" and "Yours faithfully" with a Comma

Follow your postamble with a comma, and write your name underneath it.
Dear Sir,

[blah, blah]

Yours faithfully, (This comma is correct.)

Matt Brown

Write the Salutation, Postamble and Your Name by Hand

If you're sending a letter by post, it is a common practice (to add a personal touch) to write the salutation, postamble, and your name by hand. For example (hand-written text shown in yellow):
Dear Sir,

[blah, blah]

Yours faithfully,

Matt Brown

See Also

When to use a comma with Dear, Hello, and Hi at the start of a letter When to use Ms., Miss., and Mrs.