Pending: If the cost of the invoice is not received, then the invoice status is shown as "Pending". It will likely be preliminary status when the bill is created.
Paid: When invoice is received full quantity, invoice status shall be proven as "Paid".
Underneath Paid: If the cost of the bill has been paid in part, the invoice standing is proven as "Under paid".
Over Paid: If the cost of the invoice is higher than quantity value, the status of the invoice is shown as "Overpaid".