eBay

When it comes to using Priority Mail flat rate boxes, how do I make sure I measure them correctly? for example when I was ordering for a medium flat rate box; they said the dimensions for it are 11 1/4" x 8 3/4" x 6" [outside]11" x 8 1/2" x 5 1/2" [i...

Hello, I am a new seller planning to sell a used item with USPS priority mail boxes. I never shipped a package before, and im worried of getting things mixed up. I wanted to use a medium flat rate box, but I am unsure how much will it cost to ship it...