Multi-Domain SSL


Multi-Domain SSL, also known as Subject Alternative Name (SAN) or Unified Communications Certificate (UCC), is a type of SSL certificate that secures multiple domain names and subdomains under a single certificate. This allows users to establish a secure connection to multiple websites or platforms without issuing separate certificates for each. It simplifies the management of security for organizations while providing a trusted and encrypted connection for their visitors.

Key Takeaways

  1. Multi-Domain SSL certificates, also known as Subject Alternative Name (SAN) or Unified Communications Certificates (UCC), protect multiple domain names or subdomains under a single SSL certificate, simplifying management and saving costs.
  2. These certificates provide robust encryption (up to 256-bit) and prove the website’s legitimacy by displaying a padlock icon, HTTPS prefix, and in certain cases, a green address bar to assure visitors their data is secure during transmission.
  3. Popular use cases for Multi-Domain SSL certificates include the deployment of Microsoft Exchange or Office Communications Server environments, web hosting, and managing multiple domains and subdomains while maintaining a unified security approach.


Multi-Domain SSL (Secure Sockets Layer) is an important technology term because it refers to a type of SSL certificate that allows businesses and organizations to secure multiple domains or subdomains with a single certificate.

This streamlines the process of managing SSL certificates and ensures a high level of security and encryption for data transfer between a user’s browser and the website’s server.

Implementing a Multi-Domain SSL certificate enhances user trust and confidence in the website’s authenticity and increases its credibility, as it demonstrates a commitment to data protection and privacy.

Ultimately, Multi-Domain SSL plays a crucial role in today’s digital landscape by offering efficient and cost-effective security solutions for organizations managing multiple websites.


Multi-Domain SSL, also known as Subject Alternative Name (SAN) SSL, is a vital technology serving the purpose of securing multiple domain names and subdomains under a single SSL certificate. This technology is widely employed by businesses and organizations that manage numerous website domains and want to ensure their users experience a safe and encrypted connection.

By using Multi-Domain SSL, these entities can provide a robust security solution without the hassle of managing individual SSL certificates for each domain, thereby saving time, effort, and resources. One of the core uses of Multi-Domain SSL is to simplify the management of security across a diverse collection of websites.

Enterprises with a substantial online presence often require hosting different sections or branches of their businesses on multiple domains and subdomains. By employing a single Multi-Domain SSL certificate, these enterprises can secure various domain names hosted on the same server, ensuring user data remains protected during transmission between their browser and the server.

This approach not only streamlines certificate management but also reduces the risk of domain security lapses and fosters user trust in the organization’s online services.

Examples of Multi-Domain SSL

Multi-Domain SSL (Secure Sockets Layer) certificates are digital security certificates that provide encrypted communication and protection for multiple domain names or subdomains under a single certificate. They are a cost-effective and easy way to secure various websites with one solution. Here are three real-world examples of Multi-Domain SSL:E-commerce websites: An e-commerce company owns and operates multiple online stores under different domain names, such as examplestorecom, examplestore

com, and examplestorecom. By utilizing a Multi-Domain SSL certificate, the company can secure all the data transactions for each store under one certificate, ensuring encrypted communication and providing trust to their online customers.SaaS (Software as a Service) providers: A SaaS provider offers a web-based software solution for different clients. Each client has a unique subdomain (e.g., client,, etc.), and the provider needs to ensure secure communication for each client. A Multi-Domain SSL certificate enables the SaaS provider to secure all client subdomains with one certificate, simplifying management while maintaining a high level of security.Educational institutions: A university or school may have multiple websites for various departments, such as,, and, each requiring a secure connection for faculty, students, and other users. Using a Multi-Domain SSL certificate allows the institution to cover all these different subdomains, ensuring data protection and secure login access across various departmental websites.

Multi-Domain SSL FAQ

1. What is Multi-Domain SSL?

Multi-Domain SSL (Secure Sockets Layer) is a digital certificate that secures multiple domain names and subdomains with a single SSL certificate. It allows website owners to manage the security of all their domains and subdomains in a cost-effective and efficient manner.

2. How many domains can I secure with a Multi-Domain SSL certificate?

Multi-Domain SSL certificates typically allow you to secure up to 100 domains and subdomains, depending on the provider. You can add, change or remove any domain name during the certificate’s lifetime, making it a flexible solution for businesses with multiple domains and subdomains.

3. What is the difference between Multi-Domain SSL and Wildcard SSL?

Multi-Domain SSL certificates secure multiple domain names and subdomains, while Wildcard SSL certificates secure an unlimited number of subdomains within a single domain. In other words, Multi-Domain SSL is designed for organizations with multiple domain names, while Wildcard SSL is designed for organizations with many subdomains under a single domain.

4. What are the benefits of using Multi-Domain SSL?

Using a Multi-Domain SSL certificate offers several benefits:

  • Cost-effective: Secure multiple domains with a single SSL certificate, reducing the cost of purchasing individual certificates.
  • Easy management: Manage the security of all your domains and subdomains with a single certificate, simplifying your SSL infrastructure.
  • Flexibility: Add, remove or change domain names during the certificate’s lifetime without additional costs.
  • Enhanced trust: Display the padlock icon and HTTPS on all your secured domains, increasing visitor trust and confidence.

5. How do I get a Multi-Domain SSL certificate for my website?

To obtain a Multi-Domain SSL certificate, you need to follow these steps:

  1. Select a certificate provider that offers Multi-Domain SSL certificates.
  2. Generate a Certificate Signing Request (CSR) for the domain names you want to secure.
  3. Submit the CSR to your chosen certificate provider.
  4. Complete the validation process required by the certificate provider.
  5. Upon successful validation, the certificate provider will issue your Multi-Domain SSL certificate.
  6. Install the Multi-Domain SSL certificate on your server and configure your website to use HTTPS.

Related Technology Terms

  • Domain Validation (DV): An SSL certificate verification type that validates the domain ownership by checking the WHOIS record.
  • Subject Alternative Name (SAN): An SSL certificate extension allowing multiple domain names to be secured by a single certificate.
  • Wildcard SSL: A type of SSL certificate that secures a primary domain and unlimited subdomains under a single certificate.
  • Unified Communications Certificate (UCC): An SSL certificate specifically designed to secure Microsoft Exchange and Office Communications environments, which can include multiple domain names.
  • Secure Sockets Layer (SSL): A security protocol that encrypts data transmitted between a web server and a user’s browser, providing secure communication on the internet.

Sources for More Information

  • GlobalSign: GlobalSign offers Multi-domain SSL certificates and provides extensive information about this technology on their website.
  • is a renowned SSL certificate provider known for its expertise in SSL technologies, including Multi-Domain SSL certificates.
  • DigiCert: DigiCert is a leading provider of SSL certificates and offers information and resources about Multi-Domain SSL certificates on their website.
  • GeoTrust: GeoTrust is a well-known SSL certificate provider that offers resources and information on Multi-Domain SSL certificates for visitor’s knowledge.

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