Can I Keep My Phone Number When Switching to VoIP in Australia?

Number portability -- the right to take your phone number to a new provider -- is protected under Australian telecommunications regulations. For most business numbers, including geographic numbers (02, 03, 07, 08 prefixes) and most 1300 and 1800 numbers, portability is a standard part of switching providers. This guide explains which numbers port, how the porting process works in Australia, what to expect on the day of the switch, and how to avoid the common mistakes that delay or disrupt the transfer.

Yes, You Can Keep Your Number

Australian number portability rules apply to most number types used by businesses. You do not have to give up your existing business number to switch providers, and a provider that tells you otherwise is wrong. The process is called number porting, and it is handled between your old provider (called the losing provider) and your new provider (the gaining provider).

The key facts: portability is your right under ACMA (Australian Communications and Media Authority) regulations; you initiate the port by submitting a request to your new provider; your old provider cannot legally refuse to release the number without a valid reason; and the process does not require you to cancel your old service before the port is complete. Do not cancel your existing service before the number has fully transferred -- this is the single most common mistake and it can result in losing the number permanently.

For a more detailed look at how number porting works across all scenarios, including multi-site business porting and complex migrations, see the complete guide to number porting in Australia.

Which Numbers Are Portable in Australia

Geographic numbers (02, 03, 07, 08 prefixes): Fully portable. These are the standard local area code numbers used by most Australian businesses. Geographic numbers can be ported to any registered AU carrier or VoIP provider, including hosted cloud phone systems and SIP trunk providers. There is no technical or regulatory barrier to porting a geographic number to VoIP.

Mobile numbers (04 prefix): Portable between carriers and between mobile services, but not typically to a fixed VoIP service. Mobile numbers can be ported to a different mobile carrier. Most Australian VoIP providers for business do not accept mobile number ports onto their fixed VoIP platform. If you use a mobile number as your main business number and want to switch to a business phone system, the practical solution is to set up call forwarding from your mobile to the new VoIP number, or to register a new geographic number and gradually transition contacts to it.

1300 and 1800 numbers: Portable. Non-geographic inbound numbers (1300 and 1800) are portable between providers, subject to the gaining provider supporting this number type. Confirm with your new VoIP provider that they support 1300/1800 porting before initiating the transfer. Most AU hosted VoIP providers support this. Allow 5 to 10 business days for 1300/1800 number ports, compared to 3 to 7 days for geographic numbers.

Fax numbers: Portable, but check with your new provider that they support fax-over-IP (T.38 fax protocol). If you use a fax number alongside your voice lines, confirm fax compatibility explicitly.

How the Porting Process Works in Australia

The process has five stages: submit the port request, verification, acceptance, scheduling, and cutover.

1. Submit the port request. Your new VoIP provider handles this on your behalf. You give them the number you want to port, the account holder name and address that your current provider has on file, and the account number or service reference from your existing bill.
2. Verification. Your existing provider checks the details you submitted against their account records. This is where most port delays happen: the name, address, or account number must match exactly as it appears on the account. Even a minor discrepancy (abbreviated street name, different legal entity name) can cause the port request to be rejected. Rejections add 2 to 5 business days of delay per attempt.
3. Acceptance. Once verified, your losing provider accepts the port request. They cannot refuse without a valid reason (such as an outstanding unpaid balance on the account).
4. Scheduling. A cutover date and time is agreed between the two carriers. For standard geographic number ports in Australia, this typically happens within 3 to 7 business days of the request being accepted.
5. Cutover. On the scheduled date and time, the number switches from your old provider to your new provider. Calls that were going to your old service will now route to your new VoIP system.

How Long Does Number Porting Take in Australia

For most business geographic number ports in Australia: 3 to 7 business days from request acceptance to cutover. This is the standard timeframe for a clean, uncontested port with matching account details.

Factors that add time: account detail mismatches (adds 2 to 5 days per rejection), porting from some smaller or wholesale carriers (can add 3 to 7 additional days), porting 1300 or 1800 numbers (allow 5 to 10 business days from the start), and porting large numbers of lines simultaneously. If you are porting a single geographic number from a major AU carrier (Telstra, Optus, TPG, or their subsidiaries), the process typically completes in 3 to 5 business days once the request is accepted.

For Telstra-specific porting timelines and the additional considerations that apply to Telstra accounts, the Telstra to VoIP porting guide covers this in detail.

How to Prepare Your Number for Porting

Before contacting your new provider, gather three pieces of information from your existing provider's account details:

1. The account holder name exactly as it appears on your account. For a sole trader, this is the individual's legal name. For a company, this is the registered company name. A trading name or abbreviated name will cause a verification mismatch.
2. The service address on your account. This is the installation address registered with your current provider, not your billing address or correspondence address. These can differ. Find the service address by logging into your current provider's portal, checking a recent bill, or calling their support line.
3. Your account or service reference number. This is on every bill from your current provider. Some providers call it a service number, account number, or CSP (carriage service provider) identifier. It is not your phone number -- it is the identifier for your account.

Once you have these three details, your new provider submits the port request on your behalf. You do not contact your old provider to initiate the port -- your new provider handles the carrier-to-carrier request. Your only interaction with your old provider is to ensure your account remains active (not cancelled or suspended) until the cutover completes.

The One Rule That Prevents the Biggest Problem

Do not cancel your existing service before the number port is complete. This is the single most common and most damaging mistake in the porting process. If you cancel your existing service before the number has been ported, the number returns to the carrier's number pool and can be reassigned to another customer. Once reassigned, you have no legal right to reclaim it.

Your old provider will continue to bill you until the cutover date, because your service remains active during the porting process. This overlap period -- typically 3 to 7 days -- is normal and expected. Do not interpret the ongoing billing as a reason to cancel early. The overlap is a small cost for ensuring the port completes safely.

If your existing provider contacts you after you have submitted a port request and offers to match your new provider's pricing or offers a retention deal, that is your commercial decision to make. But if you decide to stay, you must formally withdraw the port request through your new provider before the cutover date. Once a port cutover begins, it cannot be reversed.

What Happens on Porting Day

On the scheduled cutover date, your number switches from your old provider's network to your new VoIP provider's system. The changeover typically happens within a 2-hour window during business hours. During this window, there will be a brief period -- usually 5 to 15 minutes -- where calls to the number may not connect while the routing tables update across the network. This is normal and expected.

Before the cutover date, your new VoIP provider will configure your number on your new system and test it internally. On the day of the cutover, confirm with your provider's support team what time the switch is scheduled so your staff know to expect a brief interruption. For most businesses, the practical impact is minimal -- a few minutes of unavailability mid-morning or mid-afternoon.

After cutover, make a test call to your number from an external mobile to confirm it is routing correctly to your new system. Check voicemail, auto-attendant, and any ring group rules you have configured. If anything is not routing correctly, contact your new provider's support team immediately -- the first 24 hours after a port are the window where most configuration issues can be resolved quickly.

What Most Businesses Get Wrong When Switching

Giving incorrect account details on the port request. The name and address on the port request must exactly match your current provider's records. A mismatch causes a rejection, which adds 2 to 5 business days of delay per attempt. Get the exact details from your account portal or a recent bill before submitting anything.

Cancelling the old service too early. Covered above. Do not do this. Keep your old service active until you have received explicit confirmation from your new provider that the cutover is complete and your number is live on the new system.

Assuming the port request was submitted. After you sign up with a new provider, confirm with them in writing that the port request has been submitted and give them a deadline for the cutover you are working toward. Some providers have delays between signup and lodging the port request. A written confirmation with a timeline prevents surprises.

Not testing the new system before porting day. Your new phone system should be set up, tested, and working before the port cutover. The port brings your existing number onto an already-configured system -- it should not be the first time you are configuring the system. Use a temporary number or a new number on your new VoIP system for the weeks before porting to verify that call quality, routing, and voicemail all work as expected.

Your Next Steps

1. Find your account details. Log into your current provider's portal and locate: account holder name, service address, and account reference number. Write these down exactly as they appear.
2. Confirm your number type is portable. Geographic numbers (02, 03, 07, 08) and most 1300/1800 numbers are portable. Mobile numbers are not typically portable to fixed VoIP.
3. Choose your new VoIP provider and set up the system. Get your new phone system configured and tested with a temporary number before your porting date. Do not wait until porting day to configure your system.
4. Submit the port request through your new provider. Give them the account details you gathered. Confirm receipt of the request in writing.
5. Keep your old service active. Do not cancel or suspend your existing service until you receive confirmation that the cutover is complete.
6. Test after cutover. Make a test call from an external number to confirm routing, voicemail, and auto-attendant are all working correctly.

Ready to switch? Get a recommendation for an Australian VoIP provider that handles the porting process and can confirm your number is portable before you sign up.

Once your number is successfully ported to a VOIP provider, the next decision is which hosted phone system to run it on. Our guide to the best phone systems for small business in Australia compares the top AU-hosted providers by price, call quality on the NBN, porting support, and contract terms, including which providers are most straightforward to port numbers to and from.

If you are still deciding whether to switch from a traditional phone service, our guide on VOIP vs traditional phone systems for Australian businesses covers what changes and what stays the same when moving to hosted VOIP, including how number retention works in practice and what to expect during and after the porting window.