On the GeoTrust and Partner Center/GeoCenter Enrollment Pages:
If you have an active certificate issued by GlobalSign, Comodo, GoDaddy, or Entrust, Baltimore, Microsoft, SECOM, Polish CA Cetrum, USER Trust - Comodo's White Label Root, or DigiNotar the customer is eligible for a competitive replacement. In addition to receiving a discount, the customer will also receive up to 12 additional free months added onto a certificate, depending on when the current certificate expires. In order to perform this upgrade, we will connect to your server, and validate that a current active competitive certificate exists for the same fully qualified domain name on the request. If for some reason we cannot connect to your current server and validate the certificate, we will allow you to paste the certificate on the next page.