Yes, Nutcache will let you delete an invoice.
For invoices with linked expenses or worked hours, or invoices for which payments have already been made, Nutcache will first unlink those elements before deleting the invoices.
How to delete an invoice?
You can either delete an invoice from the invoice screen:
To delete an invoice, click the hamburger menu on the left side on the invoice name and select the Delete invoice option.
Or from the invoice list:
First, locate the invoice you want to delete and click the Delete invoice option from under the Action menu.
Please note that the deletion of an invoice is irreversible; once the invoice is deleted, you cannot get it back.