International buyers can search .co.uk and bid. I've had this recently with a proof set i sold, a Chinese buyer won it yet i had'nt listed it on.com which would give it international visibility. It was taken to the PO where my friend was informed that currency was not permitted to be shipped to China. My guess is that of the ebayer has 2 or 3 postal addresses and 1 might be based in the UK but they live elsewhere then they will be permitted to bid and have the item delivered to the UK address. Just as a heads up, you cannot edit an auction that has been bidded on, you can add details about the item but not a full on edit, its just Basic info you can change, but not things like where you post to, start price etc, for this, you'll need to end the auction, change the Details and then relist, but then of course, ebay get another listing fee from you.