You may use a P.O. only if you are a school.
To use a PO, once you have completed all of the details on your
order, click "Pay by P.O". You may then email your PO to us at firstname.lastname@example.org. We will
then invoice you. We cannot fill your order until we receive your PO.
Our terms are net 30 and there will be a 20% penalty for any invoice not
paid within 30 days.