There are several reasons you might want to access your Files.com site through multiple custom domains, such as if you're supporting multiple brands with one site, handling legacy integrations that rely on an old custom domain, or to minimize downtime when switching between two custom domains. Configuring your site to be accessed from multiple domains isn't directly supported by Files.com, and requires more work to manage the configuration.

SSL Certificates for Multiple Domains

In order to access Files.com from multiple custom addresses, you'll need to manage your own SSL certificate. Many SSL vendors provide a form for generating certificate signing request (CSR) for your certificate. If you wish to use Let's Encrypt for your certificate, their Certbot utility can be installed on a variety of platforms to manually generate a certificate that you can upload into your account.

You'll need to generate a CSR for and upload a certificate that uses Subject Alternative Name (SAN) that covers all of the domains you want to use. You should list the domain that will be your primary custom domain first in the certificate.

When you generate the CSR, specify all of the domains that the certificate is for. Do not use a wildcard, such as *.example.com, which is not compatible with Files.com.

If you have the option to specify the key type when generating the ticket, only RSA key types are compatible with Files.com.

You Are Responsible For Renewing Your Certificate

Because you must supply your own SSL Certificate in order to use your site with multiple domains, you are responsible for renewing the certificate. Plan to renew any expiring SSL Certificate prior to its expiration date and time.

Once your SSL Certificate Provider has provided you with your renewed SSL Certificate, import the certificate (and its intermediate certificates) just as you imported the previous one. You can activate the new certificate before the old certificate expires.

Applying and activating a renewed SSL Certificate will not change your custom domain or its dedicated IP addresses.

SAN Certificates Are Not Wildcard Certificates

You cannot use a Wildcard SSL certificate with the Custom Domain feature. Only domains which are explicitly listed in your certificate can be used as a custom domain for your Files.com site.

Custom Domain Setting

Files.com offers a setting for a single custom domain. This domain should match the first domain listed in your SSL certificate. Any links generated by the platform will use this custom domain address.

Configure Your Custom Domain

With your SAN certificate in hand, you can upload it as you would when configuring a single custom domain.

After uploading your SSL certificate, you must activate it. Once your SSL certificate is active, create your CNAME records for each domain you will use for your site.

All of the domains that will be used with your custom domain will use the same CNAME record value - an address that contains your subdomain name in the form s-[subdomain].di.app.files.com.

After you have created all of the necessary CNAME records, you can complete the setup of your custom domain by updating your custom domain setting in Files.com with the primary domain address. You can only choose one domain to be the primary custom domain of your site. This should match the first domain listed in your SSL certificate.

Accessing Your Site By Primary Custom Domain

Once you've completed configuring your custom domain with the SAN certificate, the appropriate CNAME records and the main custom domain setting, you can access the site through the web URL that matches your custom domain setting. When you do, you should be served the certificate that includes all of the domains you wish to use.

Accessing Your Site By Secondary Custom Domain

Once you've finished setting up your custom domain, you should be able to log in via web, API, WebDAV or FTPS at the alternate domain addresses from your certificate. When you do, you'll be served the certificate that lists your primary domain as the "Common name" and your other domains in the "Alternative names".

You can also access your site through SFTP at the secondary addresses, but because SFTP does not use SSL certificates, this won't provide the certificate you configured.

Share Link and Inbox URLs

Share Links and Inboxes will use your primary custom domain address to generate links. Even if you connect through a secondary custom domain, the generated URLs will use your primary custom domain.

Emailed Links

Files.com provides multiple features that will email links to the platform. This includes Inbox and Share Link invitations, Email notifications, new user welcome emails, password recovery emails and site alert emails. Any links sent by the platform will always use the primary custom domain address; there is no way to override this behavior.

Multiple Custom Domains vs Child Sites

Files.com provides a Child Site feature, creating an entirely separate site that is associated with your primary account. Each child site's content and its settings, such as users, logos, and custom domain are self-contained.

If the users for each domain would not "cross over" to other domains, then a child site may be a simpler answer for you—you can set up a separate custom domain for the child site without providing your own SSL certificate. Branding a child site with a custom domain will also solve problems with URLs generated by the platform because the child site will only have its primary domain, so the URLs will match.

If your users would need to interact with multiple domains, or you would need the same content for multiple domains, then setting up multiple domains is preferable to using child sites.