To register a .com.au domain you need an Australian presence, which for most small businesses means an ABN or ACN. The domain also has to connect to your business, usually by matching its name. You buy it from an accredited registrar for anywhere from one to five years. Once it's yours, it gives you a professional email address like hello@yourbusiness.com.au.
This guide covers who's eligible under auDA's rules, how .com.au stacks up against .au and .com, what it costs and how to set up business email so your messages actually arrive.
Who's allowed a .com.au domain
auDA runs Australia's domain names and sets the rules in its licensing rules. A .com.au has to pass two tests.
Test one: an Australian presence
Most small businesses meet this with an ABN. A company with an ACN qualifies too. So do Australian citizens and permanent residents, registered charities, incorporated associations and a list of other organisations set out in the rules. Owning or applying for an Australian trade mark also counts, but only for a domain that exactly matches the trade mark.
Test two: the name has to connect to you
You must be a commercial entity. On top of that, the domain itself must be one of these:
- A match or acronym of your company, business or personal name. A business registered as Coastline Pest Control could take coastlinepestcontrol.com.au or cpc.com.au, if they're free.
- A match of your Australian trade mark.
- A match or acronym of a related company's name.
- A match or synonym of a service you provide, goods you sell, an event you run or premises you operate. This is the rule that lets a business hold a descriptive domain for something it genuinely does.
Your details have to stay accurate for the whole time you hold it. If they change, the rules give you 14 days to tell your registrar. Registering a domain under a web designer's name or a family member's tends to bite later, usually on the day you need to prove it's yours.
.com.au, .au or .com?
You'll see three endings offered to Australian businesses. Here's how they differ under the rules.
| Ending | Who can register it | Worth knowing |
|---|---|---|
| .com.au | An Australian presence plus a name that connects to your business | The long-standing default for Australian businesses |
| .au | An Australian presence | Shorter and newer, with no name-match test |
| .com | Anyone, anywhere | No Australian rules, so good names are often taken |
Our view: make the .com.au your main address. If the matching .au is free, it's usually worth grabbing as well and pointing it at the same site. That way nobody else can use it.
What a domain costs
Domains are one of the cheapest parts of being online. When we checked VentraIP's domain page on 7 October 2026, .com.au and .au names started at $9.95 a year as an offer, against a regular price of $22.95 a year. Prices vary between registrars and offers come and go. Budget for the regular price.
Keep an eye out for letters or emails that look like a renewal invoice from a company you've never dealt with. Before paying anything that mentions your domain, check it came from the registrar you actually use.
Registering it, step by step
- Search for the name at an accredited registrar. auDA keeps a list of accredited registrars.
- Have your ABN or ACN ready. The registrar checks it against the name you've chosen.
- List your business as the registrant. For the contact email, pick one you'll still be checking in five years.
- Choose a licence period of one to five years. Switch on auto-renew.
- Store the registrar login somewhere safe. You'll need it whenever your website or email moves.
Setting up a professional email address
A professional email address runs on your own domain: hello@yourbusiness.com.au rather than a free gmail.com or bigpond.com one. It looks more established. It also stays yours if you change internet provider or move your website.
Where the mailboxes should live
Most small business email runs on one of two services. Google Workspace is Gmail with your own address, plus Calendar and Drive. Microsoft 365 is Outlook with your own address, plus Word and Excel. Google's Australian pricing page listed its Starter plan at A$9.90 per user per month before tax, after an introductory discount, when we checked on 7 October 2026. Microsoft lists its plans on its Australian business page. Both charge per person with a mailbox.
You can also run email on your web hosting. It's cheaper, but we wouldn't for a business inbox. Web servers are built to serve pages. Their mailboxes fill up fast. If the site goes down, your email goes with it.
Extra addresses without extra bills
You don't need a paid mailbox for every address. Both services let you add extra addresses, like accounts@ or bookings@, that deliver into a mailbox you already pay for. A sole trader can run three or four addresses from one inbox.
Three records that keep your email out of junk
New business email often fails quietly. Messages send fine, then land in the customer's spam folder. Receiving mail servers look up records on your domain to decide whether a message really came from you.
- SPF lists every service allowed to send email as your domain. Include your website's contact form and any booking or invoicing tool that emails customers for you.
- DKIM signs each message so the receiving server can tell it wasn't altered on the way.
- DMARC tells other servers what to do with mail that fails those checks. It can also send you reports.
Since February 2024, Google's sender guidelines have required anyone sending to Gmail accounts to set up SPF or DKIM. Bulk senders, sending more than 5,000 messages a day, need all three. A small business won't get near that number. Setting up all three properly still keeps quotes and invoices out of junk folders. It also makes your domain harder to fake.
Changing email without losing any
Already have email running somewhere? Find out where your domain's MX record points before changing anything, because that record decides where mail is delivered. Then set up the new mailboxes first. Copy old mail across. Switch the MX record last. Done in that order, nothing goes missing. Done backwards, you can lose a day of enquiries without noticing.
It helps to remember that your domain, your website and your email are three separate services, often from three different companies. Our guide to what web hosting is explains how they fit together. Building a site from scratch? How to build a website puts the domain in its place in the order.
Want us to set it up?
If you'd rather not touch DNS records, our domain and email set-up is $150 inc GST. We register or transfer the domain into your name and set up Google Workspace or Microsoft 365. Then we add the SPF, DKIM and DMARC records and test that mail sends and arrives. The domain itself costs whatever the registrar charges, passed straight on.
Already have a website on your domain? The free website check tests its speed, certificate and security headers in a few minutes.
Domain and email: quick answers
Can I register a .com.au without an ABN?
An ABN is the usual route, though an ACN or another form of Australian presence listed in auDA's rules also counts. A .com.au is also for commercial entities with a name that connects to the domain. If you're unsure, check with the registrar before paying.
How long can I register a .com.au domain for?
Between one and five years at a time. Turn on auto-renew so it never lapses by accident.
Do I need the .au if I already have the .com.au?
No. It's optional. Some businesses register the matching .au to protect the name and point it at the same website.
Can I use my domain for email without a website?
Yes. Email and the website are set up separately on the domain. You can have working email at your own address years before you build a site.
Is a free Gmail address fine for a business?
It works. An address on your own domain looks more established, though. It also never has to change, even when your internet provider or website does.