How to Migrate from Landline to VOIP in Australia: Complete Guide (2026)

Migrating your Australian business from a traditional landline to VOIP is a structured process that thousands of businesses complete every month, typically in 2 to 4 weeks with zero call downtime. This guide is built on Australian deployment realities: NBN connection types, ACMA number porting rules, and the specific steps that differ here from generic international migration guides. By the end, you will have a clear migration plan, know what to expect on cutover day, and understand what to do if something goes wrong.

Why Migrate Now? The Case Is Already Closed

The short answer: the traditional PSTN copper network is already gone. Telstra and NBN Co completed the copper decommission as part of the NBN rollout. If your business phone is still connected, it is running over NBN infrastructure, one way or another. The question is no longer whether to migrate. The question is whether you are getting a proper business VOIP service or still running on an ISP-controlled adapter that was never designed for business use.There are three reasons businesses delay migration and all three cost money. First, the feature gap. An ISP-supplied phone adapter gives you one line. If two customers call at the same time, the second caller gets an engaged tone and calls a competitor. That lead is gone permanently. Second, the professionalism gap. No hold music. No auto-attendant. No after-hours routing. No voicemail to email. These are all standard features of even an entry-level business VOIP plan. Third, the cost gap. Business VOIP plans typically cost $30 to $60 AUD per month per user and include features that would cost hundreds of dollars per month on a legacy phone system. Every month on the ISP adapter is a month of paying for less and losing leads.

The NBN Silent Migration: You May Already Be on VOIP

When Australia rolled out the NBN, ISPs quietly moved all customers from PSTN landlines to VOIP via the ATA port on their supplied modem. ATA stands for Analog Telephone Adapter. It is the green port on the back of your NBN modem that your old analog handset plugs into. This happened with zero warning, zero training, and zero explanation of alternatives.If your phone is plugged into the green port on your ISP modem, your VOIP connection is embedded in the modem's firmware. Your ISP controls it entirely. You do not have SIP credentials. You cannot move that number to a different provider without going through a proper number port. You cannot add a second line, enable call recording, set up an auto-attendant, or get voicemail to email. You have a single analog phone line that happens to travel over NBN infrastructure, administered by your ISP.This is fundamentally different from a business VOIP service. A proper business VOIP setup gives you SIP credentials you own, a hosted PBX that handles call routing and features, and a provider relationship with actual business support. The migration described in this guide is about moving from the ISP ATA service to a real business VOIP system, not about switching from analog copper to digital. That step already happened without your input.

Pre-Migration Assessment: What to Check Before You Start

A successful migration starts with a clear picture of your current setup. Work through this checklist before contacting any provider.

Current Setup Audit

List every phone number your business uses. Include your main number, any direct-dial numbers, 1300 or 1800 numbers, fax lines, and any numbers used by alarm systems, EFTPOS terminals, or lifts. Each of these will need a decision made about it during migration. Numbers you want to keep will need to be ported. Numbers no longer in use can be cancelled. Special-purpose lines (fax, alarms, EFTPOS) need separate handling as described below.For each number, note who the current carrier is, whether there is a contract or minimum term still active, and what the number is used for. This information will be required by your new VOIP provider when they initiate the porting process.

Internet Connection Assessment

Your NBN connection will carry your voice calls. Before migrating, confirm your connection type and test its quality. VOIP requires latency below 150ms and packet loss below 1% for acceptable call quality. Each simultaneous call uses approximately 80 to 100 kbps of bandwidth, so bandwidth is rarely the constraint. Latency and packet loss are what matter. Run a quality test during your busiest business hours. A standard speed test is not sufficient. Use a tool that measures latency and packet loss. Your prospective VOIP provider should be able to recommend a test or run a quality check during their sales process. See the VoIP call quality guide for full diagnostic steps.

Feature Requirements

Before choosing a provider, document what you actually need. Common business requirements include: number of staff who need to take calls simultaneously, whether you need a 1300 or 1800 number, call recording (note: in Australia you must comply with the Telecommunications (Interception and Access) Act 1979 regarding consent), auto-attendant or IVR for call routing, voicemail to email, after-hours routing to mobile, ring groups, and CRM integration. A clear requirements list makes provider comparison straightforward and prevents scope creep during setup. For broader context on phone system choices, see the business VOIP phone systems guide.

Step 1: Choose a VOIP Provider

Your VOIP provider is the most important decision in the migration. The provider supplies your SIP trunks (the voice channels your calls travel over), your hosted PBX (the call routing system), and ongoing support when things need adjusting. Choosing on price alone is the most common mistake. A provider that is $10 AUD cheaper per month but takes 48 hours to respond to a support request will cost far more when something goes wrong on the day of your cutover.Key criteria for Australian businesses: Does the provider have Australian-based support staff who can handle the business? Do they have experience with number porting in Australia, including ACMA-compliant porting processes and realistic timelines? Do they supply pre-configured handsets to reduce setup complexity? What is their SLA for porting and provisioning? Can they demonstrate successful migrations of businesses similar in size and setup to yours?The contrast with ISP-supplied services is significant. Your current ISP almost certainly cannot tell you what SIP credentials power your green port phone line, cannot advise on the right feature set for your business, and cannot migrate you to a better service without you initiating a complete exit. A specialist VOIP provider's job is to ask how your business actually works and then configure a system around that. That consultative approach is not a luxury feature. It is the standard expectation. For a comparison of the hosted versus on-premise decision, see the hosted PBX vs on-premise guide.

Step 2: Initiate Number Porting

Number porting is the process of transferring your existing phone numbers from your current carrier to your new VOIP provider. In Australia, number porting is governed by ACMA rules and administered through the industry porting framework. Your new provider initiates the port on your behalf. You do not deal with your outgoing carrier directly in most cases.Standard number porting in Australia takes 5 to 10 business days for geographic numbers (02, 03, 07, 08 area codes). This is the regulated minimum processing time. Any provider promising same-day or next-day porting for geographic numbers is either mistaken or referring to a different process. Mobile number ports are faster, typically 1 to 2 business days. 1300 and 1800 numbers have a separate porting process and can take longer. For a full breakdown of what can go wrong and how to avoid it, see the number porting guide for Australian businesses.To initiate a port, your new provider will require: the exact number to be ported, the current carrier name, the account holder name and address as registered with the current carrier, and the account number. Providing incorrect account details is the most common cause of porting rejection and delays. Get these details directly from your current carrier's billing portal or by calling their account team before submitting the port request.

Step 3: Set Up Your Hardware

While your number port is processing, set up your new VOIP hardware. Most businesses migrating from a basic landline setup will need: one or more SIP desk phones (or softphone apps installed on computers or mobiles), a router with QoS support to prioritise voice traffic, and in some cases a dedicated VOIP adapter if keeping existing analog handsets.Many VOIP providers offer pre-configured phones. The phone arrives with your SIP credentials already loaded. You connect it to your network, it registers with the hosted PBX, and calls work immediately. This is the simplest path for most small businesses. If you order unpreconfigured phones, your provider will supply provisioning instructions. Follow these exactly. Manual SIP configuration errors are a common source of setup problems.QoS (Quality of Service) router configuration ensures your voice calls are prioritised over other network traffic. Without QoS, a large file download or video stream from another device can degrade call audio. Most business-grade routers support QoS. Consumer-grade routers vary. If your current router does not support QoS, your provider may recommend an upgrade. This is worth doing before cutover day rather than troubleshooting call quality under pressure after you have gone live.

Step 4: Parallel Running. Zero Downtime Migration

Parallel running means operating your old and new systems simultaneously for a period before cutting over. This is how zero-downtime migrations work. During parallel running, your new VOIP system is configured and tested using temporary numbers or your new provider's test numbers. Your existing landline service continues to handle live calls. When you are confident the new system is working correctly, you cut over.For most small business migrations, parallel running lasts 2 to 5 business days. This gives you time to: confirm all phones are registering correctly with the hosted PBX, test inbound and outbound call quality, verify call routing rules are working as expected, test your auto-attendant script and ring groups, and train staff on any new features or the new handsets.Parallel running is particularly valuable when you have multiple staff or complex call routing. For a sole trader with a single phone number, the parallel phase may be as short as one day. The key principle is: do not cut over until you have made real test calls on the new system and confirmed everything works.

Step 5: Cutover Day. What to Expect

Cutover day is the moment your number port completes and all incoming calls to your ported number route to your new VOIP system. For most migrations, this happens automatically when the port is processed. Your provider should notify you in advance of the scheduled port completion time.On cutover day, make an inbound test call to your main number as soon as the port is confirmed. Verify it rings on the correct devices with the correct ring group configuration. Make an outbound test call and confirm caller ID is displaying correctly. If anything is not working, your provider's support team should be your first call. Have their direct number ready. Do not rely on a ticketing system on cutover day.Most issues on cutover day are minor configuration problems. Common examples: a ring group that was not updated to include the ported number, outbound caller ID set to the wrong number, or a call routing rule pointing to an old extension. These are quick fixes when you have a responsive support team. They become significant problems if you are waiting hours for a response while customers call and nothing rings.Once cutover is confirmed and working, cancel your old phone service. Do not let it linger. You will be paying for a service you are no longer using. Check whether there are any contract exit obligations. Under Australian Consumer Law, you are entitled to cancel a service that has passed its minimum contract term. If you are still in a term contract, check whether early termination applies and factor this into your migration timing.

Post-Migration: Testing Checklist and First-Week Issues

In the first week after migration, work through this testing checklist and be prepared for a small number of configuration adjustments. These are normal and your provider should handle them quickly.Inbound call testing: call your main number and confirm it rings as expected. Call during and outside business hours to verify after-hours routing. If you have ring groups, confirm all members are receiving calls. If you have an auto-attendant, test each option to verify routing is correct.Outbound call testing: make outbound calls and verify your caller ID displays correctly. If your business uses a 1300 number as its public-facing number, confirm that outbound calls show that number rather than an internal DID. Test calls to mobile and landline numbers.Voicemail and notification testing: leave a voicemail and confirm it delivers to email correctly. Check that the transcription is enabled if your plan includes it. Verify that all staff who should receive voicemail notifications are receiving them.Staff training: brief all staff on any new features they now have access to. If you have added hold music, call recording, or a new transfer process, show them how to use it. The most common first-week complaint after migration is that staff do not know how to transfer a call on the new system. A 15-minute walkthrough before go-live prevents this.

Special Cases: Fax, Alarm Systems, and EFTPOS Lines

Fax machines, alarm systems, EFTPOS terminals, and lift emergency phones all use analog phone lines and require special handling during a VOIP migration. These devices cannot connect directly to a SIP service without additional equipment.

Fax Lines

Fax over VOIP (T.38 fax protocol) works on many hosted PBX systems but reliability varies. For businesses that use fax regularly, a dedicated cloud fax service is a more reliable option than trying to run a physical fax machine over VOIP. Cloud fax services receive faxes to a number and deliver them to your email. Outbound faxes are sent from a web portal or email client. No physical fax machine required. Cost is typically $10 to $20 per month AUD for low-volume use.If you must keep a physical fax machine, an ATA adapter between your fax machine and your VOIP service can work. Ask your provider whether they support T.38 and what the expected reliability is before committing to this path.

Alarm Systems

Alarm systems that use a phone line to call monitoring companies are a significant migration consideration. Many older alarm systems use PSTN-specific signalling that is not compatible with VOIP. Contact your alarm monitoring company before migration to determine whether your alarm communicator will work over VOIP, whether an ATA adapter is suitable, or whether the alarm needs to be upgraded to a cellular communicator. Most alarm monitoring companies have handled this transition many times and will have a clear recommendation. Do not assume the alarm will continue working after cutover without confirming this.

EFTPOS Terminals

Most modern EFTPOS terminals in Australia use mobile (cellular) or Ethernet connectivity, not a phone line. If your EFTPOS terminal has an RJ11 phone jack, contact your payment provider before migration. They will advise whether the terminal requires a dedicated analog line, can be connected via an ATA adapter, or whether it should be upgraded to a cellular or IP-connected model. Running EFTPOS over a VOIP-connected ATA can work in some cases but is not recommended for high-volume payment environments without testing.

Australian Businesses: What You Need to Know

Several aspects of VOIP migration are specific to the Australian regulatory and infrastructure environment.

PSTN Copper Is Already Gone

Australia's PSTN copper telephone network was decommissioned as part of the NBN rollout. There is no copper-to-VOIP migration still ahead of you. If your phone is working, it is already running over NBN. The migration described in this guide is about upgrading from an ISP-controlled VOIP service to a business-grade VOIP platform. This context matters because some providers still market migration services as if copper is the starting point. It is not. Your starting point is an NBN-delivered voice service of some kind.

Number Porting Rules in Australia

Number porting in Australia is regulated by ACMA under the Telecommunications Numbering Plan 2015. Your current carrier is required to cooperate with a porting request unless there is a legitimate technical or contractual reason not to. If your current carrier is obstructing a port without good reason, you can lodge a complaint with the Telecommunications Industry Ombudsman (TIO). Your new provider should be familiar with this escalation path and willing to assist.You retain ownership of your geographic number. A geographic number is tied to a service area code (02 for NSW/ACT, 03 for VIC/TAS, 07 for QLD, 08 for WA/SA/NT) and can be ported to any carrier. 1300 and 1800 numbers are also portable but have a separate administration process. Mobile numbers port independently of geographic number ports.

000 Emergency Calling on VOIP

Unlike PSTN, VOIP does not automatically provide your location to emergency services when you call 000. Most Australian hosted PBX providers are required to register a service address for emergency calling under the ACMA emergency call service rules. When you set up your VOIP service, you must register a service address. If your business has multiple locations, each location should be registered separately. Verify with your provider that 000 calling is configured and tested before you fully cut over. This is a legal requirement and a safety consideration.

Power Outage Considerations

VOIP phones require power and internet connectivity to function. Traditional PSTN phones could draw power from the phone line and work during a power outage. VOIP does not. If your business needs phone access during a power outage, consider: an Uninterruptible Power Supply (UPS) for your router and VOIP phones, call forwarding rules that automatically route to a mobile number when the main system is unreachable, or a mobile softphone app that staff can use as a fallback when the office internet is down.

Australian Consumer Law and Telco Contracts

Under Australian Consumer Law, telecommunications services must be fit for purpose. If a service is not performing as described, you have rights to remediation or exit regardless of the contract term. The Telecommunications (Consumer Protections and Service Standards) Act 1999 and the TCP Code set baseline obligations for service quality and fault resolution. If your current provider is providing an inadequate service, document the faults and contact the TIO if the provider does not resolve the issue within a reasonable timeframe. You are not necessarily locked in simply because a contract exists.

Migration Timeline Expectations

A typical simple migration for a 1 to 5 person business with one main number takes 2 to 4 weeks from first contact with a provider to full cutover. The majority of that time is the regulated porting window, not setup time. The actual configuration work is usually completed in 1 to 2 days. More complex migrations involving multiple sites, dozens of numbers, or legacy equipment can take 4 to 8 weeks. Set expectations with your staff accordingly and plan cutover timing around your business cycle. Avoid scheduling a cutover during your busiest period. See the VoIP vs traditional phone comparison if you are still weighing up the benefits.

Common Mistakes When Migrating to VOIP

These are the mistakes that cause migrations to go wrong or take longer than necessary.Mistake 1: Cancelling the old service before the port completes. This is the most damaging mistake. If you cancel your existing phone line before the number port is finalised, your number will be released and cannot be ported. It may be permanently lost. Your existing service must remain active and in good standing until your new provider confirms the port is complete.Mistake 2: Providing incorrect account details for the port request. Number porting requires exact match on the account holder name and address as registered with the outgoing carrier. If these details do not match, the porting authority will reject the request and the process starts again. This adds days to the migration. Before lodging a port request, verify your exact account details with your current carrier.Mistake 3: Not testing the new system before cutover. Parallel running exists for a reason. Running a real test call on the new system before cutting over is the single most effective way to catch configuration problems without business impact. Businesses that skip this step and go live without testing are the ones that call their provider in a panic on cutover day.Mistake 4: Forgetting about special-purpose lines. Fax machines, alarm diallers, EFTPOS terminals, and lift phones all use analog phone lines and will not survive a VOIP migration without deliberate planning. Identify every analog line in your business before starting the migration and determine the correct approach for each one.Mistake 5: Choosing a provider on price alone. A $5 AUD per month saving on a plan is irrelevant if the provider takes 2 days to respond to a support request. Migration is a period of elevated risk. You want a provider with responsive, local support and demonstrated experience with Australian business migrations. This is not the time to optimise for the cheapest plan.

Your Next Steps

Use this checklist to move from reading to action.This week: Audit every phone number your business uses and document the carrier for each. Check the back of your modem to determine whether you are on an ISP ATA or an existing VOIP service. Run a latency and packet loss test on your NBN connection during business hours. Document your feature requirements: how many simultaneous callers, what routing you need, what integrations matter.Before contacting providers: Gather your current carrier account details (account number, registered name and address) for each number you want to port. Check whether any of your numbers are still in a minimum contract term and when that term ends. Identify any special-purpose lines (fax, alarm, EFTPOS) and confirm compatibility requirements with those service providers.When evaluating providers: Ask specifically about their porting experience with AU geographic numbers and 1300 numbers. Ask how they handle pre-configured handset provisioning. Ask what their support hours are and how to reach them on cutover day. Ask for references or case studies from businesses of a similar size. For guidance on the hardware side of the setup, see the NBN VOIP setup guide.After signing up: Confirm your port lodgement date and the expected completion date. Set your cutover date for 1 to 2 days after the expected port completion to give yourself buffer. Brief your staff before cutover day. Have your provider's direct support number saved, not just their ticketing portal.Not sure which VOIP system is right for your business? Tell us about your setup and we will point you in the right direction. The Get a Recommendation page takes 2 minutes and gives you a personalised starting point.

How long does it take to migrate from a landline to VOIP in Australia?

A simple migration for a 1 to 5 person business with one main number typically takes 2 to 4 weeks from first contact with a provider to full cutover. The bulk of that time is the regulated number porting window of 5 to 10 business days for geographic numbers. The actual system setup and configuration is usually completed in 1 to 2 days. More complex migrations involving multiple sites or dozens of numbers can take 4 to 8 weeks.

Can I keep my existing phone number when switching to VOIP?

Yes. Number porting allows you to transfer your existing geographic number (02, 03, 07, 08 area codes), 1300 number, or 1800 number to a new VOIP provider. Your new provider initiates the port on your behalf. You must keep your old service active and in good standing until the port completes. Do not cancel your existing service before receiving confirmation that the port is finished.

What happens if my internet goes down after I migrate to VOIP?

If your internet connection fails, VOIP calls will not work until connectivity is restored. To mitigate this, set up a call forwarding rule in your hosted PBX that automatically forwards calls to a mobile number when your VOIP system is unreachable. Most hosted PBX providers support this as a standard failover option. You can also install a softphone app on your mobile to handle calls over mobile data when your office internet is down.

Do I need to buy new phones when migrating to VOIP?

Not necessarily. If you already have SIP desk phones they may be compatible with your new VOIP service. Check with your provider. If you have analog handsets currently plugged into a green port on your NBN modem, those cannot connect directly to a SIP service. You can either replace them with SIP phones (Yealink, Grandstream, and similar are common choices in Australia at around $80 to $250 AUD per handset) or use an ATA adapter to connect your existing handsets to the new service. Many providers offer pre-configured handsets as part of their onboarding package.

Will my fax machine work after migrating to VOIP?

Physical fax machines connected directly to a SIP service have variable reliability. Fax over VOIP uses the T.38 protocol and works on many hosted PBX systems, but it is sensitive to the quality of the connection. For businesses that use fax regularly, a cloud fax service is a more reliable option. These services provide a fax number, deliver received faxes to email, and allow outbound faxing from a web portal. Cost is typically $10 to $20 per month AUD. If you must keep a physical fax machine, confirm T.38 support with your provider before committing.

Is my alarm system affected by a VOIP migration?

Potentially yes. Alarm systems that communicate via a phone line (PSTN or ATA) may not be compatible with a standard VOIP SIP connection. Contact your alarm monitoring company before migrating. Options typically include: connecting the alarm via an ATA adapter (works in some cases), upgrading the alarm communicator to a cellular (4G/5G) or IP module, or using a dual-path communicator that uses both cellular and IP. Most alarm companies have handled this transition many times since the NBN rollout and will have a clear recommendation for your specific system.

Do I need a contract to get a business VOIP service in Australia?

Most Australian business VOIP providers offer both month-to-month and contract plans. Month-to-month plans typically cost slightly more per month but allow you to exit without penalty. 12 or 24-month contracts usually offer lower monthly rates and may include free or discounted hardware. Under Australian Consumer Law, telco contracts must include minimum service standards and you are entitled to exit if those standards are not met. If you are new to a provider, a shorter initial term or month-to-month arrangement reduces your risk while you evaluate service quality.

Related reading:

• PSTN copper shutdown
• ISDN to VoIP migration
• NBN VoIP setup