GeoTrust QuickSSL Premium Wildcard offers a quick & cost-efficient solution for businesses to quickly secure their single main domain (i.e. www.yourdomain.com) AND unlimited sub-domains (i.e. mail.yourdomain.com, ftp.yourdomain.com) with one simple DV SSL/TLS certificate. With a nice automatic authentication and issuance process, you can have this cert in 10 minutes or less. With GeoTrust being one of the most trusted names in the online encryption industry, your customers can gain some assurance knowing that your site is protected by known & recognized security brand in just minutes. This is an ideal option for an SMB that has any number of sub-domains that need security as well and/or someone future-proofing their site for sub-domains that may come in the near future.
This GeoTrust® Wildcard TLS certificate can protect multiple domains, HOWEVER, those multiple domains must be sub-domains that all use the same exact base domains. For example, by using *.site.yourdomain.com in the common name field, you can protect test1.site.yourdomain.com, test2.site.domain.com, etc. with this one certificate.