Single SSL Certificate for Multiple Websites: Possibilities and Advantages of Multi-Domain SSL Certificates


When you decide to purchase an SSL certificate for any of your business websites, one of the critical questions that come to mind is whether it’s possible to use one certificate for multiple domain names or not. Because if you have multiple websites and plan to build some more, purchasing separate SSL certificates for each of them and managing each of those certificates can become a cumbersome process. In such a situation, it’s normal for this question to come to mind. And in this article, we’ll try to find out the answer to this question for you. But before we begin, let’s go through a short introduction to SSL certificates.

What is an SSL certificate?

An SSL certificate is a code that binds your business’s identity with your domain name. It’s issued by a certificate authority (CA) after complete verification of your business identity, which is why it’s unique for every business. No one can get a certificate issued in the name of your business after you’ve got it. Once installed on your server, the certificate serves as proof to show anyone that the website is your official website. If someone else tries to create a cloned version of your website on a similar-looking domain name, they can be caught easily because their website won’t have the SSL certificate of your business, due to which a “Not Secure” label will appear near the URL.

With that being said, let’s explore the types of SSL certificates so we can answer the question that’s the base of this article.

Types of SSL certificates

The market of SSL certificates is one of the most diverse markets in the world of digital technology. There are many types of certificates based on various criteria. However, based on the number of domains that they can protect, there are the following types of SSL certificates available in the market:

  • Single-domain SSL certificates: These certificates protect only one domain. You can’t protect even any of your subdomains with them, which seriously limits their ability in today’s environment where almost every business website creates at least one subdomain.
  • Wildcard SSL certificates: These certificates protect one root domain and all other subdomains created below it. As a result, they’re more applicable for any business purpose than a single-domain SSL certificate.
  • Multi-domain SSL: Multi-domain SSL certificates as the name suggests, can protect up to 250 different domains (FQDN) and subdomains on a single server. You also have the freedom to add additional domain names in the given SAN (subject alternative name) field. Due to this flexibility, they become significantly more helpful for business requirements than the other two certificates.
  • Multi-domain Wildcard SSL certificates: The multi-domain wildcard certificate is a blessing for organizations who wish to secure multiple SAN, subdomains, and multi-level subdomains. One can also choose to add up to 100 SAN wildcard domains during the lifecycle of a certificate.

Each of these certificates comes in Domain Validated (DV), Organization Validated (OV) variants, and Extended Validation (EV) variants (except for wildcard certificates, which don’t offer EV option), but that is a broad topic that should be left for discussion in another article. Right now, we shall stick to the question we were trying to answer, for which we’ve collected enough background information by now.

Single SSL certificate for multiple domain names: Is it possible?

The answer is YES! And the solution required to do that is in multi-domain SSL certificates. As explained above, such a certificate can protect all your domain names and all your subdomains created under them. The domains and subdomains are added as subject alternative names (SANs) to the Certificate Signing Request (CSR) of these certificates. Accordingly, a certificate with those SANs is generated and issued by the certificate authority (CA). The certificate works on all domains and subdomains for which it has been issued once appropriately installed on the web server.

Benefits of using multi-domain SSL certificates.

So far, we were exploring merely the possibility of using a single certificate for multiple domain names. Now we’ll also explore whether it’s beneficial or not. And the thing is that there are many benefits of using a multi-domain SSL certificate to protect all your domains. Some of them include:

  • One-time verification process: Purchasing individual SSL certificates for all your domains would require you to verify your identity, business existence, and domain ownership again and again. On the other hand, with a multi-domain SSL certificate, you need to go through this process only once at the time of certificate issuance.
  • Scalability: It’s a highly scalable solution. With multi-domain SSL certificates, you can add as many domains and subdomains as you wish without having to worry about whether your existing certificate will protect it or not. This saves a lot of time and also reduces your administrative costs.
  • Ease of management: Certificate management also becomes significantly more manageable when you need to take care of only one certificate. Otherwise, if you have a bunch of certificates, you’ll end up spending much more time renewing them and managing them as your business grows and new websites add up.
  • Cost savings: Finally, buying a multi-domain SSL certificate costs significantly less than purchasing multiple single-domain or wildcard SSL certificates. Initially, the price may seem more, but in the long run, your savings will be way more than the initial cost. Nowadays, many cheap multi-domain SSL certificates have arrived in the market to reduce your initial cost as well.


In short, it’s not just possible to have one SSL certificate for all your domains and subdomains but also advisable to do the same. There are many benefits of using a multi-domain SSL certificate, so you should consider using it for your business rather than any other kind of certificate. The only limitation is that they tend to be a bit costly. Still, if you can afford it, you should purchase them because you won’t face any scalability issues with your certificate as you grow.

If you still have any questions about these certificates on your mind, feel free to ask them in the comments. If not, get your multi-domain SSL certificate today to protect all your domain names and websites.


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