Are negative lightning invoices possible?
Discussion
Good evening #nostr
Now that I ate and had a little break it's time to ask a more detailed question:
A friend of mine works in a business that wants to go completely cashless. They are thinking about offering lightning payments. The only problem are refunds.
If you buy a beer you have to pay 2€ for the cup. If you bring the cup back you get the 2€ back. Is there a way that the cashier can generate a QR or lightning bill with a negative amount? The customer only has to scan and accept and get his sats back.
The whole process has to be fast, just like refunds on bank cards. We are talking about hundreds of customers within half an hour (football).