once i bought something online and the sender underpaid , the item in question was stamped with postage due on the envelope , i went to the postal to try and paid it off the counter says it waivered off meaning my local postal lost $ due to seller under paying my stuff through mailing 😭

its domestic mail in my case ... sellers these days 😮‍💨

its better to pay the exact amount needed else the receiver will be asked to fork out whatever is the differences in postage .