"My Invoices" can be accessed via the "Billing" tab in the WebManager. This section will display any outstanding invoices associated with your account. It will provide the Invoice Number, Amount Due, Date of Invoice and will indicate how many days late the payment is.
If an outstanding invoice is listed within your WebManager, it can be paid by clicking the "Pay Now" button. Once the invoice is paid, it will no longer show under "My Invoices".