When you purchase a postage label on eBay Delivery, you select a price band, each price band has very precise restrictions in terms of Weight, Dimensions (Longest, Second Longest, Smallest side) and Overall size ( calculated by taking the two shortest sides of your parcel summed together. Then multiply the sum by 2 and finally add the length. The total is the overall size).
Such restrictions are visible from the service selection before you purchase the postage label and they can change depending on the carrier, the service and the selected weight band. So it is important to carefully read them before you dispatch your parcel:
When you dispatch your parcel you need to make sure that weight, dimensions and overall size does not exceeds what is permitted by the price band you have confirmed. If the chosen carrier detects a discrepancy, Packlink will issue to the sender an underpayment fee that varies depending on the type of discrepancy and the carrier: Additional charges