I have an invoice with only taxes (that are indeed to be booked in the bookkeeping). But the cost amount is actually zero. I cannot enter 0 on an invoice.
Workaround: put amount of 1 in the invoice, and afterwards use the button to "empty" the invoice. It's not ideal but it works...
Workaround: put amount of 1 in the invoice, and afterwards use the button to "empty" the invoice. It's not ideal but it works...