Customise invoice numbers
To add a prefix to your invoices or to start the unique numbers from something other than zero is a little bit of a hidden trick in Quaderno, but it's easy when you know how!
Go to your most recent invoice, click the ellipsis icon (…) and then Edit in the dropdown.
You'll be taken to a screen that looks like this:
That "Number" field is the invoice number - you can see in this example that the invoice is 00002.
Add your prefix (or change the number to another positive number). Scroll to the bottom of the page and hit Save changes.
Now, when your next invoice rolls in, it will be completely identical in invoice number to your most recent invoice except that the number part will have been incremented by one.
For example, 2016/Q2/00456 will lead to 2016/Q2/00457.
Boom! Custom invoice numbers with no fuss.