I need to send to my buyer another invoice for an additional amount

[bp-46]

I offered an item for sale via the auction process, and it sold. In the seller's decscription of the item I specifically stated that the buyer should wait for my invoice before making payment.  Before I had a chance to prepare and send an invoice to the buyer, the buyer's payment arrived via paypal.  The amount paid was insufficient in that it did not include the cost of the packaging for the item to be sent to the buyer via Australia Post.  I emailed the buyer requesting the additional payment, and the buyer now requires another invoice for the additional charge.

How can I now send an invoice for the outstanding charge.

[silversterio2]

The listing did have calculated post and did show a different price to buyers in different states but when you're using the postage calculator, you have the option to add a packaging and handling fee .

This is what should have been done rather than asking the buyer for more money afterwards.