A subdomain lets you create a distinct section of your website — like a blog, store, or support hub — under your existing domain, without registering an entirely new one. Adding a subdomain is a DNS-level change, and the general process is similar no matter which provider manages your domain's DNS. This guide covers the concept and the general steps; check your specific DNS management interface (including Avalon's client area, if that's where your domain is managed) for the exact menu names.
What Is a Subdomain?
A subdomain is a prefix added to your main domain name. If your domain is yourbusiness.com, a subdomain might be blog.yourbusiness.com or shop.yourbusiness.com. Subdomains are created through DNS records:
- An A record points a subdomain directly to an IP address — use this when the subdomain should resolve to a specific server.
- A CNAME record points a subdomain to another domain name instead of an IP address — use this when the subdomain should follow wherever that other domain points.
General Steps to Create a Subdomain
While menu names vary between providers, the underlying steps are consistent:
- Log in to your domain's DNS management area. This is usually found under a "DNS," "DNS Zone," or "Domain Settings" section of your provider's control panel.
- Find the option to add a new DNS record. Look for something like "Add Record" or "Add New DNS Record."
- Choose the record type. Select "A" if the subdomain should point to an IP address, or "CNAME" if it should point to another domain.
- Enter the subdomain name. This is just the prefix — for example, enter "blog" to create blog.yourbusiness.com, not the full domain.
- Enter the value. For an A record, this is the IP address of the server hosting the subdomain's content. For a CNAME, it's the target domain name.
- Set the TTL (Time to Live). This controls how long other servers cache the record before checking for updates — an hour is a common default.
- Save the record. Most DNS changes take effect within an hour, though full global propagation can occasionally take up to 48 hours.
If you need to update or remove a subdomain later, you'll typically find and edit the same record from the same DNS management screen.
Why Use a Subdomain?
- Cost-effective expansion — create new sections of your online presence without buying an additional domain.
- Better content organization — separate distinct functions, like blog.yourbusiness.com for content and support.yourbusiness.com for customer help, keeping your main site focused.
- Improved user experience — visitors can go directly to the section they need instead of navigating through unrelated content.
- Safe testing environments — a subdomain like staging.yourbusiness.com lets you trial changes without affecting your live site.
- Targeted SEO — each subdomain can be optimized for its own specific keywords and audience.
- Geographic or language targeting — subdomains like uk.yourbusiness.com can serve region-specific content without cluttering your main site.
Securing a Subdomain With SSL
Any subdomain that handles sensitive information — logins, payments, or personal data — needs an SSL certificate, which encrypts the connection between your site and visitors.
- Check your existing SSL coverage first. A standard SSL certificate typically covers only your main domain, while a wildcard SSL certificate (covering *.yourbusiness.com) secures your main domain and all its subdomains under one certificate.
- Buy SSL for a single subdomain if you only need to secure one, rather than paying for wildcard coverage you don't need.
- Consider a wildcard certificate if you have — or plan to add — multiple subdomains that all need encryption.
- Free options exist, such as Let's Encrypt, though these typically need to be renewed roughly every 90 days.
After installing SSL, confirm the subdomain loads correctly over "https://" and, where possible, set up automatic redirection from the unencrypted version so visitors always land on the secure page.
Frequently Asked Questions
How long does it take for a new subdomain to go live?
Most DNS changes take effect within about an hour, though full propagation across all servers globally can occasionally take up to 48 hours.
Can I add more than one subdomain to my domain?
Yes — there's generally no limit to how many subdomains you can create under a single domain.
Does adding a subdomain cost extra?
Creating the DNS record itself is typically included with your domain and DNS management. Additional hosting or services you choose to run on that subdomain may have their own costs.
My subdomain isn't working — what should I check first?
Double-check that the record type (A vs. CNAME), name, and value were entered correctly, and allow up to 48 hours for full propagation before troubleshooting further. If it's still not resolving after that, contact your DNS provider's support team.
