If your item is on eBay, there should be no need to contact the seller to get the post code of the item's location. Simply follow these steps:
1) Click the "Is this an eBay item?" checkbox
2) Enter the eBay item ID number (this is the long number located in the top right hand corner under the description tab)
3) Click the "Import eBay Item Details" button
4) Shiply automatically imports the item description, photos and collection address details