Related webpage:  Sending your buyer an invoice

After your listing ends and before the buyer completes checkout, you can send your buyer an invoice. You can also send your buyer a revised invoice if they’ve purchased more items from you. 

Related webpage: Sending a combined invoice

When a buyer purchases more than one item from you, you can send that buyer a combined invoice. A combined invoice lets a buyer send you a single payment for multiple purchases, saving you both time. You can also offer shipping discounts to buyers who purchase multiple items from you.