“Yours sincerely” is a traditional closing phrase used in formal correspondence to convey respect and professionalism. It signifies that the writer knows the recipient by name and has a genuine connection to the content of the letter. ‘Yours sincerely’ is commonly used in a formal letter wherein the author knows the name of the respondent. ‘Regards’ is commonly used for informal communication that is written to close friends or relatives. Yours sincerely is also British. Americans tend to reverse the order and write Sincerely yours. When I worked in England, I was told that to write Sincerely without the Yours was very bad form. Now, of course, Sincerely is a common and acceptable close for American business letters. Which words to capitalize… Only the first word is capitalized: (YOURS) SINCERELY definition: 1. used to end a formal letter that is sent to a particular person: 2. used to end a formal letter…. Learn more.