To cancel a cash desk receipt, there are three possible ways:
1. Write a credit note. Go to sales-> records-> credit notes. Click on new, choose a dummy "cash sales customer" or create one. Choose the article and save.
2. Put the same article you sold in the cash register if you sold it with a serial number please add it as well. Click into amount and alter it to "-1" confirm with enter and change, if necessary, the price also confirm with enter.
HINT: If there is a little red triangle, the system demands another confirmation. if it disappeared everything is now correct.
3. Go to sales->cash register->withdrawal/deposit. Choose a withdrawal with the correct amount and mention the original receipt.