In closing your letter, it is important to use an appropriately respectful word or phrase.
Letter Closing Examples
Sincerely, Regards, Yours Truly, and Yours Sincerely - Are the simplest and most useful letter closings to use in a formal business setting. These are appropriate in almost all instances and are excellent ways to close a cover letter, or an inquiry.
Best Regards, Cordially, and Yours Respectfully - The letter closings fill the need for something slightly more personal. These are appropriate once you have some knowledge of the person to whom you are writing. You may have corresponded via email a few times or had a face-to-face, or phone interview.
Warm Regards, Yours Faithfully, Best Wishes, With Appreciation - These letter closings are also appropriate once you have some knowledge or connection to the person to whom you are writing. Because they can relate back to the content of the letter, they can give closure to the point of the letter.
Take the time, when writing a letter closing, to be sure you're using a word or phrase that makes sense for the type of letter you're writing. If you're not positive about the best way to close your letter, using a simple, basic term like sincerely or regards.