What are the address requirements for mail piece?

Postcards, Letters, Self-Mailers And Booklets. 

All of these have the same addressing options. First, put the barcode with the address. It must be at least a 1/2 inch from the right edge as well as at least 5/8 from the bottom edge. You need to stay 1/8 inch away from text and images and the maximum distance the address can be from the bottom of the mailer is 3.5 inches. We usually recommend to customers to leave an area of about 4 inches by 2 inches for the address and barcode. This area must be clear of UV coating, varnish, images and other text. The second option is to use the bottom right area for the barcode, which is referred to as the barcode clear zone. If you want to use this area you need to keep all images, color and text out of the bottom 5/8 area. The address would then have the same placement requirements as your first option.

Flats.

These are required to have the address block in the upper half of the short edge. For instance, with an 8.5-inch-by-11-inch mailer, you would need to address from the top of the piece down only to 5.5; don’t address below the 5.5. There is no barcode clear zone for flats. You will need to use an address block that includes the barcode, a 4-inch-by-2-inch clear area, no varnish, UV coating, text or images. You must also make sure that you have at least a .125-inch clearance for the address block from the edge of the piece and any text or graphics.