The following table includes the names and websites for the certification authorities that issue Unified Communications SSL certificates for Exchange Server and Skype for Business or Lync Server.
| Certification authority | Website |
|---|---|
| Comodo | http://www.comodo.com/ |
| DigiCert | http://www.digicert.com/unified-communications-ssl-tls.htm |
| GeoTrust | http://www.geotrust.com/ssl/ssl-certificates-san-uc/ |
| GlobalSign | http://www.globalsign.com/ssl/buy-ssl-certificates/unified-communications-ssl/ |
| GoDaddy | https://www.godaddy.com/ssl/ssl-certificates.aspx |
| Thawte | https://www.thawte.com/tls-ssl/compare-multi-domain-certificates |
If you are a vendor seeking to join the certification program, see How to Join for requirements and available programs.