Shipping small parcels in the United States may seem simple — attach a label, hand it to the carrier, and wait for delivery. However, in real-world practice, extra fees, delivery delays, and returned packages happen. Below are the 6 most common mistakes  we’ve identified for your reference. Mistake #1: Incorrect Measurements — Underestimating Box Size It’s common to: Only measure the box without including external packaging Have actual dimensions larger than what was declared