but I am curious if that is only in case with a larger discrepancy, and if it is even worth our time to add the .25 or .50 inch to the measurements The packages get measured by laser and the billed dimensions adjust if necessary. You can see any differences between your claimed dims by looking at your shipping history comparing it to your invoice. The invoice will tell you the dimensions billed and if there were differences egregious enough to change the billing. Does your shipping tool allow decimals? Some of the FedEx Ship Manager fields don't take decimals. You're supposed to round up to the nearest inch (or switch to centimeter units I guess). Would love to know if other shipping tools take decimals. I use box specified dimensions if available. Occasionally the lasers add an extra inch somewhere, usually not big enough to change anything. Good luck if you need to dispute something, refunds are basically off the table this year. More on reddit.com

However, I decided to look in help under Smart Post just to refresh myself and there it said that if any side of box is over 12 inches there would be a surcharge. What the heck? Mercari gave SP as an option for this particular item. I took it to Fedex (an actual store) and the clerk scanned ... More on reddit.com

did you ship in a big box? how about a really really long box? you might have been charged dim weight L x W x H/139 vs 13lb, whichever is greater I don't know the over size limit for fedex but it might have hit that too Quite a few people seem to think this is a FedEx thing. This is incorrect, USPS, ups, FedEx will all audit postage and will claw back incorrect postage. More on reddit.com

Them having a business account doesnt mean our drivers should have to deal with a package beyond the max dimensions. More on reddit.com