Multi Domain SSL Certificates

A multi-domain SSL Certificate secures several separate names on one SSL Certificate, using Subject Alternative Names (SANs). The names can be different domains, such as example.com and mybusiness.net, along with subdomains like www.example.com, mail.example.com, and shop.example.com, all under a single SSL Certificate.

This suits an organization that runs more than one website, or one that uses several subdomains for different services, and wants a single SSL Certificate with one expiry date rather than a separate SSL Certificate for each name. Coverage runs from a few names to hundreds, with more available as additional SANs.

What a Multi Domain SSL Certificate Secures

The Subject Alternative Name (SAN) extension lets one SSL Certificate list several hostnames that are all treated as valid for it. Each name on the list is secured in the same way, so a group of sites can share one SSL Certificate instead of holding one each.

The names can mix separate domains and their subdomains, which fits a business that runs several brands, a set of service subdomains, or both together. Coverage runs from a few names to hundreds, and further names can be added as additional SANs as the group grows.

One SSL Certificate for Several Sites

A multi-domain SSL Certificate replaces the separate SSL Certificates you would otherwise order for each site, so one SSL Certificate and a single expiry date cover the whole group. That leaves fewer dates to track and one reissue process rather than several.

The saving grows with the number of names one SSL Certificate covers, and adding a name later is cheaper than starting a new SSL Certificate for it. Everything stays in one place as the group changes.

Encryption and Protocols

A multi-domain SSL Certificate uses a 2048-bit RSA key with 256-bit symmetric encryption, over the Transport Layer Security (TLS) 1.2 and 1.3 protocols, with SHA-256 hashing. The same encryption applies to every name on the SSL Certificate.

Each secured name connects over HTTPS with the padlock shown, and the SSL Certificate supports the encryption requirements of the Payment Card Industry Data Security Standard (PCI DSS). Compare Encryption Algorithms 🔗

Validation for Each Name

Every name on a multi-domain SSL Certificate is validated on its own before the SSL Certificate is issued. For each name you confirm control by replying to an e-mail at an approved address, adding a Domain Name System (DNS) record, or placing a file at a set location on that name.

Domain Validation (DV) checks only control of each name, so issuance is quick. Organization Validation (OV) and Extended Validation (EV) add a verified organization identity that applies to every name on the SSL Certificate. Understand Validation Methods 🔗

Multi Domain Compared with Wildcard

A multi-domain SSL Certificate and a Wildcard SSL Certificate solve different problems, and the right choice depends on how your names are arranged.

When a Multi Domain SSL Certificate Fits

A multi-domain SSL Certificate fits when you need to secure several different domain names, when you want an exact list of the names covered, or when you are securing a mix of domains and subdomains across more than one domain.

When a Wildcard SSL Certificate Fits

A Wildcard SSL Certificate fits when you mainly need to secure many subdomains of a single domain, or when you add subdomains often and want them covered without changing the SSL Certificate. Explore Wildcard Coverage 🔗

Where you need both at once, meaning several wildcard domains on one SSL Certificate, an option combines the two. Compare DV Wildcard Multi Domain 🔗

The Trustico® Multi Domain Range

Trustico® offers multi-domain SSL Certificates across every validation level, so you can match the SSL Certificate to how much assurance your sites need. The domain-validated options issue quickly and suit most websites. Compare DV Multi Domain 🔗

The domain-validated range includes a lower-cost entry option alongside the Trustico® and Sectigo® branded SSL Certificates, each covering the same names at a different warranty level. Compare the PositiveSSL DV Multi Domain 🔗

Where a verified organization identity is needed, an Organization Validation option secures the same names with checked company details behind each one. Compare OV Multi Domain 🔗

For the most rigorous identity check across several names, Extended Validation options are offered under the Trustico® and Sectigo® brands. Compare EV Multi Domain 🔗

Choosing the Right Option

If your sites need encryption and fast issuance without identity checks, a domain-validated multi-domain SSL Certificate is usually enough. If visitors or partners need to see a verified organization behind your sites, an Organization Validation or Extended Validation option carries that identity across every name.

If every domain in your portfolio needs full subdomain coverage rather than a fixed list of names, a wildcard multi-domain option covers unlimited subdomains on each domain instead. Understand Extended Validation 🔗