Understanding Primary, Alias (or Parked), Addon and Sub domains

We understand that the types of domains can be confusing. This article will help you understand the difference between all the domain options and assist you in assigning additional websites/domain names to your cPanel account - whether that’s a Subdomain, Addon or Alias/Parked domains.

Lets get all your domains under one roof.

If you would like to add a new domain to your account on which you'd like to host a new website you'll need to add it as an addon domain - see the Addon Domain section below.

Quick Reference

This table gives you a really quick overview - you can read about each type of domain in more detail further down this document.

Domain Type

Can host a unique website

(counts towards unique websites in your plan)

Can host unique email addresses

Primary domain

e.g. primary.co.uk



Addon domain

e.g. secondary.co.uk



Sub-domain (of primary or addon domain)

e.g. subdomain.primary.co.uk or subdomain.secondary.co.uk



Alias domain

e.g. alias.co.uk



Sub-domain (of alias domain)



Primary Domain

This is the main domain for your cPanel account. Your primary domain is served from the public_html/ folder within your home directory. Your home directory is the directory you see when you first connect using FTP e.g. a file located in your home directory at /public_html/mypage.html would be served to the world as http://your.primary.domain/mypage.html

Please ensure you upload your website to the correct folder - usually /public_html/ for your primary domain. Uploading your website into the top level directory of your home directory isn't recommended; it usually won't work, and creates a mess!


cPanel > Domains > Subdomains

A subdomain is a subsection of your website that can exist as a new website without a new domain name. You can use subdomains to create memorable URLs for different content areas of your site. For example, you can create a subdomain for your blog that is accessible through blog.example.com and www.example.com/blog

Subdomains of primary or addon domains become new unique websites.

To create a subdomain, click the Subdomains icon within the Domain section in cPanel.

Subdomains can be used to create entirely separate websites, for example if you have www.myprimary.domain you could add a sub-domain to create blog.myprimary.domain.

Ensure you upload your website files to the correct Document Root folder - /public_html/subdomain-document-root/

Email and subdomains

Subdomains are treated separately in terms of email handling - i.e. you can maintain mailboxes for all of your subdomains entirely independently.

Addon Domain

cPanel > Domains > Addon Domain

By adding additional new domains as Addon domains, you are setting up a new unique website within your hosting, which means your new domain will have it's own website address e.g. https://www.addon.domain

Any addon domain becomes a new unique website - they create a new vhost (Virtual Host). Also note, that subdomains of addon domains also become new unique websites.

To add an Addon domain, click the Addon Domains icon within the Domain section in cPanel.

New Domain Name - Enter the new Addon domain here (don't include the www - the system will automatically work with www as well once you're finished).

Subdomain/FTP Username - cPanel creates a subdomain and an FTP account for the Addon domain. The example shown would create a subdomain called myaddondomain.myprimarydomain - this is primarily to allow the statistics software to function correctly. An FTP account will also be created (if you tick the Create an FTP account... tick box) with a login username of e.g. [email protected] and a password matching the one you set in the Password fields.

Document Root - This is where you want to keep the files for your addon website. This is normally a subdirectory of your public_html/ directory, and by default it uses the domain name you are adding as the name of that directory, e.g. public_html/addondomain.co.uk - however, you can chose any directory name you like.  If you are going to host several websites, then it is a good idea to place the document root at the top level, so instead of the Document Root saying public_html/domain2.com it would simply say domain2.com. This avoids a number of problems that can arise from the use of mod_rewrite in your primary domain.

In the above examples then either /public_html/myaddondomain.co.uk/myfile.html (document root as sub-domain under public_html) or /myaddondomain.co.uk/myfile.html (document root at top level) would be served to the world as http://myaddondomain.co.uk/myfile.html

If you are adding a handful of domains with the same basic name (e.g. domain2.com, domain2.co.uk, domain2.org etc) then you might get a message saying that the Subdomain or FTP User already exists. This is because cPanel will, by default, try to use the first part of the domain name for the Subdomain/FTP username, so you will have to change the default to something else for each of your domains.

Ensure you upload your website files to the correct Document Root folder.

Email and Addon Domains

Addon domains are treated separately in terms of email handling - i.e. you can maintain mailboxes for all of your domains entirely independently.

Alias (or Parked) Domain

cPanel > Domains > Aliases

Alias or parked domains don't have any hosting directly attached to them. They can have email accounts and can be forwarded or redirected to other websites.

To add an Alias domain, simply click the Aliases icon within the Domains section in cPanel.

Enter the new domain and click 'Add Domain'.

Once you add an Alias domain to your cPanel account you'll need to add a Redirect - by clicking on 'Manage Redirection' next to the domain you've added and enter the URL to redirect to. Once you've done this the Alias domain will open the website it's redirected to.

Email and Alias Domains

Alias domains are treated separately in terms of email handling - i.e. [email protected] is a completely different mailbox account to [email protected]

Reducing your Unique Websites

Your Primary domain, any addon domains and any subdomains of your primary/addon domains each count towards your unique websites, as they create a new vhost (Virtual Host) - you can run a totally separate website on your primary domain, any addon domains and any subdomains of your primary or addon domains.

If you are only using an addon domain for email, you can remove it and re-add it as an alias domain.

You will need to remove any subdomains of the addon domain before you can delete it (be sure to note their unique Document Root before you delete them if you plan to re-add them once you've added the domain as an alias).

If you have existing email accounts using this addon domain (or subdomains) their email files will not be deleted when you remove the addon domain or subdomains. Simply re-add the domain as an alias and recreate the subdomains (using the exact same Document Root you noted above) and the mailboxes will be accessible again.

Removing an addon domain or it's subdomains won't delete any associated files or directories (just the vhost and DNS information) - however any websites will no longer be accessible. If you need to continue hosting a site you will need to leave the domain/subdomain as an addon.

Errors when adding an alias or addon domain

When adding a domain name which is already assigned to another Krystal cPanel account on another server, you will see this message.

When adding a domain name which is already assigned to this or another Krystal cPanel account on this server, you will see this message.

In the case above, the domain krystal.co.uk cannot be added because it is already associated with another user.

You will be unable to Park(alias) or Addon a domain if it is already either

  • A primary domain for another Krystal cPanel account
  • An alias (parked) domain or Addon domain on another Krystal cPanel account - even the same one you are working with.

If you need help figuring out where the domain has been duplicated, please raise a support ticket from your Krystal Client Area.

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