If you already have a hosting account and want to run a second or third website without buying a new plan, the answer you're looking for is an add-on domain. But many people confuse it with subdomains and parked domains — terms that sound similar but work very differently. This guide explains all three clearly, along with a step-by-step walkthrough for adding one in DirectAdmin.
What Is an Add-on Domain?
An add-on domain is an additional domain name that you attach to an existing hosting account. Each add-on domain points to its own dedicated folder inside your hosting space, so the website it hosts has completely separate content from your main domain — even though both share the same hosting account and server resources.
Example: Your hosting account's primary domain is mybusiness.com. You add myshop.com as an add-on domain. Files for myshop.com are stored in /domains/myshop.com/public_html/, completely separate from mybusiness.com. Visitors who go to myshop.com see a different website from mybusiness.com — while both run off the same hosting account.
Quick summary: Add-on Domain = different domain + different content + separate folder, all on the same hosting account.
How Is an Add-on Domain Different from a Subdomain?
A subdomain is a prefix attached to your primary domain name. For example: shop.mybusiness.com or blog.mybusiness.com. It is still "part of" your main domain — not a separate domain registration.
The key difference: a subdomain requires no separate registration and costs nothing extra. You create it within your hosting control panel, and it exists as long as your primary domain is active. An add-on domain, by contrast, must be a fully registered domain with its own annual registration fee.
Side-by-side example
- Subdomain: blog.mybusiness.com — still part of mybusiness.com, no separate registration needed
- Add-on Domain: myblog.com — an independent domain, must be registered separately
Generally, subdomains work well for segmenting your existing website — for example, shop.mybusiness.com for an e-commerce section or blog.mybusiness.com for content. Add-on domains are better suited for websites that need their own distinct brand identity, separate client projects, or completely unrelated purposes.
How Is an Add-on Domain Different from a Parked Domain?
A parked domain (also called a domain alias) is a domain that points to and displays the exact same content as your primary domain. There is no separate folder — visitors who type the parked domain will see the same website as the primary domain in every way.
A common use case for parked domains is buying multiple TLD variants of your brand name to prevent competitors from registering them. For instance, you own mybusiness.com and also register mybusiness.net and mybusiness.co.th, parking both on your main domain. No matter which address a visitor types, they land on the same website.
Easy reminder: Parked Domain = different domain name, same content (mirror). Add-on Domain = different domain name, different content.
Comparison Table: Add-on Domain vs Subdomain vs Parked Domain
| Feature | Add-on Domain | Subdomain | Parked Domain |
|---|---|---|---|
| Example | myshop.com | shop.mybusiness.com | mybusiness.net |
| Content | Separate (its own folder) | Separate (its own folder) | Identical to the primary domain |
| Separate domain? | Yes — must be registered | No — uses the main domain | Yes — must be registered |
| Domain cost | Yes (annual renewal fee) | None | Yes (annual renewal fee) |
| URL seen by visitor | myshop.com | shop.mybusiness.com | mybusiness.net (or redirects to .com) |
| Best for | Multiple websites, separate projects | Sections of existing site (blog, shop) | Brand protection, shorter URL variants |
How to Add an Add-on Domain in DirectAdmin
DirectAdmin on AsiaGB hosting supports add-on domains through the Domain Setup menu. Follow these steps:
- Log in to DirectAdmin — Open your browser and go to your DirectAdmin URL (e.g.,
https://server.asiagb.com:2222). Sign in with your hosting account username and password. - Go to Domain Setup — From the DirectAdmin dashboard, click "Domain Setup" under the "Your Account" section.
- Click "Add Another Domain" — Press the "Add Another Domain" button at the top of your domain list.
- Enter the new domain name — Type the domain you want to add (e.g.,
myshop.com) in the Domain field. Do not include http:// or www. - Configure options — DirectAdmin will automatically create a folder at
/domains/myshop.com/public_html/. You can choose to enable www subdomain and SSL certificate options as needed. - Click "Add" — Click the Add button to save. DirectAdmin will automatically create the DNS zone and directory structure for the new domain.
- Upload your website files — Use File Manager or FTP to upload files to
/domains/myshop.com/public_html/. Your new domain website is now ready.
DNS Configuration Before Adding an Add-on Domain
Before your add-on domain can serve a website, you must configure its DNS to point to the AsiaGB server. Here is what you need to do:
1. Create an A Record
Log in to the DNS management panel at your domain registrar (AsiaGB, GoDaddy, or wherever the domain is registered) and create an A record:
- Hostname: @ (or leave blank to point the root domain)
- Type: A
- Value: The IP address of your AsiaGB server (found in your Welcome Email or DirectAdmin > System Info)
- TTL: 3600 (or default)
If you also want www.myshop.com to work, add a second A record with Hostname: www pointing to the same IP address.
2. Wait for DNS Propagation
After setting up the A record, DNS changes can take anywhere from 15 minutes to 48 hours to propagate fully, depending on your registrar and the TTL value. You can check propagation status using an online tool such as whatsmydns.net.
3. Install an SSL Certificate
Once DNS has propagated, go back to DirectAdmin and navigate to SSL Certificates to issue a free Let's Encrypt SSL for your new domain. This ensures visitors can access your site securely over https://.
Limitations to Know Before Using Add-on Domains
- The domain must already exist — You cannot add a domain that has not been registered yet. Register it first, then add it to your hosting account.
- Domain registration is a separate cost — Each add-on domain has its own annual registration and renewal fee, which is not included in your hosting price.
- Limit depends on your hosting plan — Each hosting package supports a different number of add-on domains. Check your plan details before adding more domains.
- Shared resources — All websites on the same hosting account share disk space, bandwidth, and inodes. If one website consumes too many resources, it may affect the performance of others.
- Security scope — Because all domain files live under one account, a security compromise of that account would potentially affect all websites on it simultaneously.
Who Should Use Add-on Domains?
Add-on domains are a cost-effective and convenient option for the following groups:
Owners of Multiple Websites
If you manage several small to medium websites — for example, a company website, a promotional site, and an online store — consolidating them on a single hosting account via add-on domains can significantly reduce monthly costs compared to buying separate hosting for each one.
Web Developers and Agencies
Developers who build websites for multiple clients can use a single larger hosting plan and add each client's domain as an add-on domain. This reduces overhead and is easier to manage than juggling multiple separate hosting accounts — especially for smaller client projects.
Businesses Running Multiple Landing Pages
If your marketing team needs separate domain names for different campaigns — such as promotion2026.com or newyearsale.com — add-on domains let you create dedicated landing pages per campaign without buying new hosting for each.
Hosting Resellers Getting Started
If you want to offer basic hosting to clients before committing to a full reseller plan, add-on domains are an easy and affordable starting point. That said, once you have several clients, upgrading to a proper Reseller Hosting plan is recommended so each client gets their own isolated account.
Tip: Before adding a second or third domain, check how many add-on domains your current hosting plan supports. AsiaGB's Business plan supports multiple add-on domains and is a good fit for anyone managing more than one website.
Frequently Asked Questions
Can I get a free SSL certificate for an add-on domain?
Yes. Every add-on domain added to an AsiaGB DirectAdmin account can have a free Let's Encrypt SSL certificate installed. You just need the domain's DNS A record to point to the AsiaGB server before issuing the certificate.
What happens to add-on domains when I migrate hosting?
When migrating, you need to: (1) transfer all domain files to the new hosting account, (2) update the DNS A records for all domains to point to the new server IP, and (3) set up each add-on domain again on the destination hosting account.
Which is better for SEO — an add-on domain or a subdomain?
For SEO, if you want the new website to build its own independent authority and rankings, a separate add-on domain is generally preferred. Subdomains can sometimes inherit authority from the main domain, but Google increasingly treats subdomains as separate sites anyway. The choice depends on your specific strategy and whether you want the new site to stand on its own brand.
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