How to Migrate from a Traditional PBX to a Cloud PBX System

To migrate from a traditional PBX to a cloud PBX, you audit your existing numbers and call flows, confirm your internet connection can carry voice reliably, choose a cloud platform, port your numbers across, and run both systems in parallel until the new one is proven. Done in that order, the switch is low-risk and your customers never notice a change. Skip the preparation, though, and you can lose numbers, drop calls, or discover too late that your EFTPOS terminal depended on a line you just cancelled.

Why businesses are moving off traditional PBX systems

A traditional PBX is a box on your wall that routes calls over physical phone lines. It served businesses well for decades, but the copper network it typically relies on is being progressively withdrawn across New Zealand, replacement parts for older systems are getting harder to source, and every change — a new extension, a reworded voicemail greeting — tends to need a technician visit.

A cloud PBX replaces that hardware with a hosted service. Your phones connect over your internet connection, the system is managed through a web portal, and staff can answer the business line from a desk phone, a laptop, or a mobile app wherever they happen to be working. You pay per user per month instead of maintaining ageing equipment, and adding or removing users takes minutes rather than a site visit.

The migration itself is where things go right or wrong, so it pays to work through it methodically.

Step one: audit what your current system actually does

Before you talk to any provider, document your existing setup properly. Most businesses discover their phone system does more than anyone remembered.

List every phone number you own: the main line, direct dial numbers (DDIs), 0800 numbers, and fax numbers. Then map your call flows — what happens when someone rings the main number, whether calls go to an auto attendant or ring a group of phones, where they land after hours, and who has voicemail. These rules need to be rebuilt in the new system, and the audit is your specification.

Just as important: list everything else plugged into your phone lines. EFTPOS terminals, monitored alarms, lift emergency phones, and fax machines often share the same copper lines as your PBX. None of these move across to a cloud PBX automatically, and each needs its own plan — usually an IP-based replacement — before the old lines are cancelled. Finally, check the contract end dates on your current lines and calling plans so you are not caught by early termination fees.

Check your internet connection before you switch

A cloud PBX is only as good as the connection underneath it. Voice traffic uses very little bandwidth compared with everyday browsing and file syncing, but it is sensitive to latency, jitter, and congestion — the things that turn a call robotic or drop it entirely.

On a healthy fibre connection, most businesses have far more capacity than voice will ever need. The practical checks are quality rather than speed: make sure your router supports Quality of Service (QoS) so voice packets are prioritised over downloads, confirm your switches and cabling can support the handsets you plan to use, and test the connection during your busiest period, not at 8am on a quiet Monday.

It is also worth planning for the day your fibre goes down. A 4G or 5G backup connection keeps your phones running through an outage, and most cloud platforms can fail calls over to mobiles automatically. If you are unsure whether your network is voice-ready, a review of your internet and networking setup before migration is far cheaper than troubleshooting call quality after it.

Choose the platform that fits how your team works

Not every cloud phone system suits every business, so match the platform to your call flows rather than the other way around. Compare the features you actually documented in your audit: auto attendants, call queues and hunt groups, business-hours routing, call recording, mobile apps, and reporting.

If your team already runs on Microsoft 365, it is worth weighing a dedicated hosted PBX against Teams Calling, which adds proper phone numbers and calling to the Teams client your staff use every day. Businesses with reception-heavy call handling often prefer a traditional hosted PBX experience with desk phones; office-and-remote teams often find calling inside Teams simpler.

Number porting: keeping the numbers your customers know

Your phone numbers are a business asset, and New Zealand's number portability process lets you take them to a new provider. Your new provider submits a port request to your current one, and on an agreed date the numbers switch across.

One rule matters more than all the others: never cancel your existing phone service before the port has completed. A cancelled number can be lost entirely, and recovering it ranges from difficult to impossible. Keep the old service active until your numbers are confirmed live on the new platform.

To keep the port smooth, make sure the account details on the porting form exactly match your current provider's records — mismatched account numbers or business names are the most common cause of rejected ports. Flag anything complex early, such as 0800 numbers or large DDI ranges, as these need more coordination than a single line. Schedule the port for a quiet period, because there can be a brief window during cutover when calls do not connect, and have your new provider confirm the date in writing.

Cut over in stages, then decommission the old system

The lowest-risk migrations run both systems in parallel. Set up the cloud PBX first on temporary numbers: build the call flows from your audit, connect the handsets and softphone apps, and have staff make test calls internally and to mobiles. Train the team on the basics — transferring calls, picking up queues, using the mobile app — while the old system is still doing the real work.

Port your numbers only once everything tests cleanly. That makes porting the final switch rather than a leap of faith. After cutover, monitor call quality and check that every routing rule behaves as designed, especially after-hours handling, which is easy to miss during business-hours testing.

Once you are confident — a couple of weeks of normal operation is a sensible benchmark — cancel the old lines, watching for any notice periods in the contract, and dispose of the old hardware. Solution Squad plans and manages cloud PBX migrations end to end for businesses across New Zealand, from the initial audit through porting and cutover. Call 0800 900 777 or get in touch to talk through your current setup.