"Yours sincerely" is a commonly used phrase in formal letters to end the correspondence. However, there are several synonyms for it that can add variety to your writing. Some of the alternatives include "Kind regards," "Best regards," "Warm regards," "Yours faithfully," "Yours truly," "Respectfully," "Sincerely yours," "With gratitude," "With appreciation," and "Cordially." These salutations can be used depending on the context of the letter and the relationship between the sender and recipient. Using different synonyms for "yours sincerely" can help you convey your message in a more personalized and professional manner.