Hi Marito

You cannot delete the invoice. Only canceling the invoice is possible.

CANCELLING INVOICE RESTRICTIONS:
INVOICES TO WHICH YOU HAVE APPLIED PREPAYMENTS: You cannot cancel an invoice to which you have applied a prepayment. You must first reverse the prepayments.

INVOICES YOU HAVE MATCHED TO PERMANENTLY CLOSED PURCHASE ORDERS: You cannot cancel an invoice that you matched to a permanently-closed purchase order.

PREPAYMENTS: You cannot cancel a prepayment that you have applied to an invoice. You must first unapply any prepayments and void the payment that paid the prepayment. You can then cancel the prepayment.

GL DATE: You cannot change the GL Date if you use Encumbrance and the distribution has been encumbered or is part of a reversal pair.

The only way to do is to void the payment then cancel the invoice from invoice workbench only.

Hope that may help.

Regards.