This switch-a-roo happened to me also. READ the box carefully. It must say "flat rate". The boxes are the same except for those words. They are right next to each other, sometimes they are mixed together. I'm always sending "care" packages to my grown children. One time I had a large "what I thought" was a flat rate box full. I sent my husband off to mail it while I was at work. Later that night, he asked how often I send packages because he thought it was expensive. He paid almost $30 to mail it. When my daughter received it, I asked her to check on the box. Sure enough it was not flat rate. My lesson was learned.