Ultimately, if someone is determined not to pay for an auction that they've won, there's little that you as a seller can do other than simply not ship them the item and leave negative feedback afterward. But there are a few nudges that you can apply to buyers to encourage them to come through before you give up and relist.
- Send an invoice. eBay has provided tools to send winning bidders an invoice stating the winning bid amount, the shipping cost, and any additional charges for which they are responsible before shipment can occur. To use this functionality, visit My eBay and click on the "Sold" link on the left side of the page under the "All Selling" header. Then, find the auction in question and select "Send Invoice" from the drop-down list next to it.
- Send them an email message. If the buyer doesn't respond to the invoice in a timely manner, send them a personal email message (their address will appear in the confirmation email that you received from eBay at auction end). Explain that they've won the auction, that by placing a bid they entered into a binding contract, and that they are now responsible for making the payment that they promised to make. Clearly give instructions in such an email that the buyer can follow in order to pay you, especially if you don't accept PayPal and need them to send an alternate form of payment to a mailing address.
- Give them a phone call. Some sellers won't be comfortable with this notionand rightly sobut for high value items or items for which you're determined to do everything in your power to close the deal, this is an option. Obtain the winning bidder's contact information, which according to eBay rules must include a working phone number, and give them a call to demand payment or work out some kind of deal that is acceptable to the both of you.
- File a non-paying bidder dispute with eBay. When you file this kind of dispute, eBay notifies the buyer directly that they are responsible for paying the winning bid amount plus any additional fees like shipping or insurance. If the buyer ultimately fails to respond or pay, your final value fees will be credited back to your account and the buyer will be warned. Buyers that are repeatedly warned about nonpayment for won auctions will be suspended.
- Send a second-chance offer to another bidder. If you are so inclined, you can use the My eBay system to send a second-chance offer to another bidder on your auction. The offer, sent through eBay, gives them the chance to buy the item at their highest bid and gives you the chance to move an item for which the top bidder didn't come through.

