It depends on the layout you choose.
If you choose address on the first page, it'll be printed on the top third of the first page of your letter.
Address on a separate page means we'll insert a page containing nothing but the address, return address and postal barcode into your letter.
Address on the back page means we'll print it on the back of the last page in your letter. This is great for letters with an odd number of pages.
Address and picture on the first page is printed on the top third of the first page of your envelope and unlike the other formats that are inserted into dual windowed, it's inserted into large windowed envelope. You can put an image or text that is visible through that large window to the right of the mailing information.