What happens if I ship an item through USPS that weighs more than what the shipping label states?

Question

I am trying to ship a package that weighs around 1 lb. So on the shipping page, I put in 1 lb and 0 oz. Now after I paid for the label I found out my package actually weighs 1 lb and 3 oz, which is supposed to cost $2 more. What happens if I just drop it off at my local shipping center? Will they return my shipment?

Answer 1

They will either return the package for insuficient postage or they will ship the package and charge the person who receives it for the difference.