With the advent of server name indication (SNI) several years ago, the number of different kinds of SSL certificates that are available has multiplied several times. It’s no longer the case that websites need to have a dedicated IP address to use SSL — there are now many different options for shared hosting situations where multiple websites reside on a single IP address.
How Do I Use One SSL Certificate for Multiple Domains?
If you need to use one SSL certificate for multiple domains, your best bet is a SAN SSL certificate or multi domain SSL certificate. Multi domain certificates use SANs, or the subject alternative name (SAN) field, which allow them to secure up to 250 different domains using a single certificate.
The ideal use case for this certificate IS shared hosting scenarios. During the generation of the certificate signing request (CSR), you simply list each domain you’d like to secure in the SAN fields, as many as you need (up to 250). Most multi domain certificates come packaged with two to four SANs, with more available for purchase per your needs.
Once you’ve submitted the CSR, you’ll need to undergo validation and every listed domain will need to satisfy a domain control check. Multi domain SSL is available at all validation levels, from DV or EV. In fact, if you want to put the EV indicators on subdomains it’s your only option — there’s no such thing as an EV wildcard SSL certificate. The CA/B Forum strictly forbids such a certificate being issued. This means that there’s one SSL certificate for multiple subdomains if you use the SAN fields of a multi domain SSL certificate.
Purchase a Multi Domain SSL Certificate & Save Up to 89%!
We offer the best discount on all types of Multi Domain SSL Certificates such as those offered by major CAs such as Comodo CA, Sectigo, GeoTrust, and Symantec. We offer the best prices in the industry with Multi Domain SSL Certificates starting as low as $18.02 per year.
Anything Else I Should Know About SSL for Multiple Domains?
There is one drawback to a multi-domain SSL certificate: key exposure. The more widely your public/private key pair is used, the less secure it becomes. There are a range of exploits that leverage brute force attacks made side-by-side across every domain using those keys in order to crack them and exfiltrate information.
This can be combated by rotating keys regularly and using a key exchange scheme that provides perfect forward secrecy.
But make no mistake about it, it is possible to use one SSL certificate for multiple domains.
Top Multi-Domain SSL Certificates of 2020
|Features||Comodo Multi-Domain SSL Certificate||Thawte Web Server SSL Certificate||Geotrust True BusinessID Multi-Domain||Comodo UCC SSL|
|Price for 1 year||$129.00||$79.00||$155.00||$130.00|
|Price for 2 years||$113.00/yr||$69.00/yr||$136.00/yr||$114.00/yr|
|Price for 3 years||$107.50/yr||$65.83/yr||$129.17/yr||$108.33/yr|
|Price for 4 years||$104.81/yr||$64.19/yr||$125.94/yr||$105.62/yr|
|Price for 5 years||$101.14/yr||N/A||N/A||$101.92/yr|
|Multiple year options|
|Domains secured||Secures WWW & NON-WWW Domain and up to 250 Multiple (FQDN) Domains||Secures WWW & NON-WWW Domain and up to 250 Multiple (FQDN) Domains||Secures WWW & NON-WWW Domain and up to 250 Multiple (FQDN) Domains||Secures WWW & NON-WWW Domain and up to 250 Multiple (FQDN) Domains|
|Issuance speed||1-3 Days||1-3 Days||1-3 Days||1-3 Days|
|Total number of san domains||250||250||250||250|
|Free san included||2||N/A||4||2|
|Validation required||Organization and Domain Validation||Organization and Domain Validation||Organization and Domain Validation||Organization and Domain Validation|
|Notification level in browsers||Domain Name and Business Name Shown on Certificate||Domain Name and Business Name Shown on Certificate||Domain Name and Business Name Shown on Certificate||Domain Name and Business Name Shown on Certificate|
|Encryption strength||256-Bit SHA-2||256-Bit SHA-2||256-Bit SHA-2||256-Bit SHA-2|
|Browser compatibility||99.9 %||99.9 %||99.9 %||99.9 %|
|Includes site seal|
|Daily malware scanning||No||No||No||No|
|Free vulnerability assessment||No||No||No||No|
|Green address bar||No||No||No||No|
|Refund policy||15 Days||15 Days||15 Days||15 Days|
|Read More||Read More||Read More||Read More|