The addressee of a letter is identified by the attention line on the envelope. According to the United States Postal Service, the address instructions’ attention line should always be placed at the top. For example, it might read “John H. Doe”.
The street address is placed after the attention line when mailing mail to a home. The final line includes the city, state, and zip code. In a business letter, the company name appears on the line after the attention line, and the same address information appears on the next two lines. It’s not necessary to use the word “attention” in its exact form.