Create negative receipts to reimburse without the original receipt

[Josse]

Hello,
We are a non-profit organization and we have a festival coming next month. 
When a customer order a drink, he must pay 2.- deposit for the cup and will get reimbursed when returning the cup.
Is there a way to create a negative article of 2.- to reimburse the deposit as it won't be possible to retrieve the original ticket.
Thanks

[Georg]

Hello
It is not possible to create a negative article but you can use the Open Tickets feature instead.
You can add a drink to the open ticket and when customer will return you a cup, you will back him his money.
If it will help you, you can leave the price field blank in the item's settings to indicate its price (deposit) upon sale.
Or you can set 0 price for the items and write the amount of the deposit in the Open Ticket comments.

The Open Tickets
https://help.loyverse.com/help/open-tickets