The heading of a business letter should contain the return address (usually two or three lines) followed by a line with the date.
The heading is indented to the middle of the page in the modified block and semiblock styles. It begins at the left margin in the block style.
If the stationery is imprinted with the return address, then the return address may be omitted.
Sometimes a line after the address and before the date may include a phone number, a fax number, an E-mail address, or the like.
Particularly if the address uses three or more lines, it is good to skip a line before the date. When using the block style, always skip a line before the date.
Always include the date.
Example:
Acme Explosives, Inc.
100-B Dry Gulch Alley
Lonesome Coyote AZ 85789
(602) 555-5555July 14, 1997