Hi Kopen,

Thanks for your response, but I forgot to mention that they have already paid for the item, and I have have searched in the drop down box in "Manage orders", and there is no selection to amend the invoice once paid to include postage.

If you select 'reply' to the Paypal notification, that will give the buyer's actual email address. Then send them an invoice through Paypal for the postage.

Then you are correct. Once paid another invoice cannot be sent.

Do as dave suggests to send a payment request in PayPal for postage.

Thanks Dave, good tip to know, but unfortunately I didn't receive a paypal notification, all I received in my email from ebay saying item is sold and has been paid for.

I have searched high and low in my inbox, deleted, junk box and didn't receive any notification from paypal about payment. I'm not sure if ebay blocks paypal payments "notifications" through ebay or I need to change the way my paypal is set up. I get notification when I sell on other platforms, and when I purchase an item on ebay and send payment through paypal. 

If you're on Managed Payments, I suspect there won't be a Paypal notification. Otherwise, the Paypal transaction should give you an email address.

Bad idea. Paypal fees, at a minimum, are non-refundable, so an instant hit to the bottom line.