This is due to the "remainder box" mechanism. Packing List: Remainder boxes (the last box that doesn't reach the standard quantity) are listed as a separate line because they have different dimensions and weight from regular boxes and need to be recorded separately. Commercial Invoice: Remainder boxes are merged back into the main product line. The invoice only summarizes the quantity by product name and does not distinguish remainder boxes. It is normal for these two documents to have different line counts—this is not an error.