Introduction

An addon domain is a powerful cPanel feature that allows you to host a completely separate website with its own unique domain name, all from within your single cPanel account. For example, if your main domain is example.com, you can add my-new-site.com as an addon domain. To your visitors, it will look like a completely independent website. cPanel handles this by creating a new folder in your account for the new site’s files. This guide will show you exactly how to create an addon domain in cPanel.

The Security Risk of Addon Domains

When you use addon domains, you are hosting multiple websites under a single cPanel user. You should be aware of two main risks:

Cross-Site Contamination: Because all your sites share the same file system, if one site is compromised (for example, through a vulnerable plugin), the attacker may be able to access, read, or infect all other sites in that same cPanel account.
Resource Contention: All addon domains share the same pool of resources (like memory and CPU). A sudden traffic spike or a script error on one site can slow down or crash all the other sites in your account.

For the best security and stability, we strongly recommend creating a separate cPanel account for each of your primary domains.

Prerequisites

A Linux server with the WHM control panel installed.
WHM or cPanel credentials.

Step-by-step Instructions

Log Into cPanel on the account to add the domain on.
Click Domains under the Domain section.
Click the Create A New Domain button.
Enter the domain name to add in the Domain text box.
Deselect the “Share document root (/home/username/public_html) with “domain.tld”.” option.
Enter the directory where you want the files for this domain to exist.
Click the Submit button.

Frequently Asked Questions (FAQs)

A Subdomain is a prefix added to your existing domain (for example, blog.yourdomain.com). An Addon Domain is a completely different domain name (for example, my-new-site.com) that you host and manage from within your main cPanel account.

This is the most critical step. If you leave this box checked, your new domain will simply show the same content as your main website. By unchecking it, you tell cPanel to create a new, separate folder for your new website’s files, allowing it to function as a truly independent site.

For the best security and performance, the recommended method is to create a brand new, separate cPanel account for your new domain. If you have already added the site as an addon domain, you can follow our guide to convert it into its own cPanel account.

There are two common reasons for this:

You forgot to register the domain: You must purchase and register the domain name (e.g., from a domain registrar) before you can add it in cPanel.
You haven’t pointed the DNS: After adding the domain, you must go to your domain registrar and point your new domain’s ‘A’ record to your server’s IP address.