We need a number so that our check will be applied to the appropriate invoice
We need the date so that we can calculate any "late payment" terms.
The description will vary with type of invoice. If a purchase order was issued, the purchase order number should be included on the invoice. Other identifying dates or numbers should be included where the purchase order does not exist. If billing is partial or interim, the period of time or identifying part should be noted.
The charge should be itemized when appropriate.
This item should denote when payment is due so that we avoid any "late payment" charges.
To assure that we are properly credited, we need to correct name and full address of the party to whom our remittance should be sent.