A buyer won 2 items he paid for the 1st on ebay's invoice. New to ebay after a long absence I incorrectly marked the second item paid and posted then sent both off.
How can I now raise a new invoice for the 2nd item.
I would email the buyer and explain my mistake. You could send a payment request to his phone number which you will have now; or make up a special ebay listing for the postage amount. It all depends on the goodwill of the buyer in the end.
