Can I pay for open invoices online? Victoria Phucas April 12, 2021 13:45 Updated Follow Yes, you can now pay open invoices in your My CLSI account by selecting “Order History,” adding the invoice to your cart, then checking out. Related articles Can I make a payment online without a credit card? How do I submit a purchase order? What are the payment options for the online store? How do I access invoices and purchased PDFs? Can I order with a purchase order through the online store?