If you signed up from irise.com, you can update your billing information online.  Upon sign-up, you should have received an email with your Order ID and billing account credentials (which are different than the credentials you use to log into iRise Definition Center).  

If you signed up after July 2016, you can update your billing information in the iRise Customer Portal. Your Order ID can be found in any of your invoice notification emails. If you can't find this information, contact us and we will help you out.

If you signed up before July 2016, you can update your billing information here:

https://sites.fastspring.com/irise/order/s/<your-order-id>

 can be found in any of your invoice notification emails.  If you can't find this information, contact us and we will help you out.