Quoted wrong postage

[cycas77]

I have made a mistake with the postage on an auction item and someone has bid on it. I am trying to get in touch with the bidder to tell them and give them the opportunity to retract their bid if they are unwilling to pay the correct postage. When I go on to advanced search there is no option to contact bidder.. Any ideas to help me? Thanks.

[**peaseblossom**]

If you cilck on where it says number of bids on your listing you'll see the bidder's ID.   Click on that and you should see a contact link.  

But you won't be able to change the postage once the listing ends or revise now there are bids (even if that bid is cancelled).   So it might be best to end the listing early and relist with correct postage.  Click on the dropdown menu next to the item on your selling page > End listing. Or use this link:
https://www.ebay.co.uk/help/ip?topicId=4146