Add to existing order & invoice

[y2ksita]

My buyer paid for their items but wants to add additional items to order. I have agreed to sell additional items and combine shipping. I don’t see an option to invoice or modify order. Do I have to cancel order and have them resubmit? 

[wooden_flower]

No, you can combine multiple payments into a single shipment using bulk shipping.

https://gslblui.ebay.com/gslblui/bulk

If the buyer overpays on the shipping on the additional item, you can send a little refund - select send refund next to the item in your list of sold items.