What is the format called where all parts of a letter start at the left margin?

The format in which all parts of a letter start at the left margin is known as the block style. In this style, the sender's address, date, inside address, salutation, body of the letter, closing, and signature line are all aligned to the left without indentation at the beginning of each paragraph. This format is commonly used in business correspondence due to its clean and organized appearance, making it easy to read.

Block style is typically preferred for formal letters as it conveys professionalism. The consistency in alignment enhances readability, which is important in ensuring that the message is clearly communicated. In contrast, the indented style would require each paragraph to be indented, while APA format refers specifically to guidelines for academic papers and citations, not letter formatting, and the full-block style is another name that could apply to block style. However, specifically referring to block style provides clarity in context.