Why does my invoice show 0.00 in the preview
When creating an invoice with Billings Pro, and you find that the preview shows $0.00 for the invoice total, you may not have marked your slips as done. Billings Pro will only invoice slips that are marked as done to ensure you are only billing for work that has been completed.
To mark your slips as done, go to the working slips tab in your project and click the button that says done beside the completed slips. Once marked as done, there will be a checkmark beside the slip instead of a button.