Are you the seller or the buyer?
eBay doesn't ship anything, so if you're the buyer it will be the seller who doesn't ship to Scotland. Sellers are allowed to exclude specific regions of the UK to which they do not deliver.
If you're the seller, as has been said you may need to rearrange delivery by Royal Mail. Or pay a courier excess charge for delivery. These complications (and the opposition of some buyers to excess charges) are why some sellers do not deliver there.