The shipping label isn't being accepted because incorrect dimensions and/or weight were assigned to the package. If there is a slight difference in the DIM weight of the label and the DIM weight of the package, please contact Support. We can provide you a new label. You also may have the option of paying for the difference in postage out of pocket. In the interest of getting the package shipped ASAP, this is encouraged.
In the case that an entirely new label is required, SidelineSwap can reimburse you in site credit up to the amount paid for by the buyer for shipping. Please provide SidelineSwap and the buyer with the new tracking number. SidelineSwap will also need a picture of the receipt.