Replace Your Business Phone System, Keep Every Number
Replacing an ageing business phone system? You keep every number, usually the cabling and often the handsets. Find your make and model and the move that fits.
Handsets you can only replace secondhand. A maker who left the phone business years ago. A copper line with a switch-off date on it. Most businesses don’t replace a phone system because they want new features — they replace it because the ground moved underneath the old one. So here is the answer to the question everyone asks first: you keep your numbers. Every one of them, ported across, ringing on the new system on cutover day. SIP Connect replaces ageing business phone systems from Greensborough, and we don’t sell the legacy brands we move you off.
Five signals it’s time to replace
You rarely get one dramatic warning. It is usually two or three of these at once, and once they stack up the decision has effectively been made for you.
No spares left.
A handset dies and the only replacement is a secondhand unit off an auction site with no warranty. When your phone system depends on the used market, it is a risk you are carrying rather than a system you are running.
The maker has stopped.
End of sale, end of support, or a full exit from the market — no more firmware, no more security fixes, no more bug fixes. The box works right up until the day it doesn’t, and then nobody is obliged to help.
The lines are going away.
ISDN has been wound down by most carriers and copper phone services are being withdrawn address by address as the PSTN switch-off rolls through. Any system that needs traditional lines has a deadline in its future, whether or not the hardware is healthy.
You’re moving premises.
Lifting an ageing PBX and re-cabling it into a new office costs real money and buys you nothing. A business relocation is the cheapest moment you will ever get to change systems, because you are paying for a cutover either way.
You’re paying per handset.
Older platforms charge for every extension, every port card and every feature licence, so hiring one person triggers a hardware conversation. Modern systems don’t work that way — 3CX, for one, is licensed by simultaneous calls rather than per extension.
What you keep: numbers, cabling and often the handsets
Start with the numbers, because it is the fear that stops most businesses picking up the phone in the first place. Your landline numbers move to the new system through number porting — the same process that moves a mobile number between carriers. Your 1300 and 1800 numbers come across too. Nothing on your signage, your website or your vehicles has to change.
Cabling usually stays exactly where it is. If your building is wired with Cat5e or Cat6 to each desk, that is precisely what an IP phone system wants: the phones plug into the same data network your computers use and draw power over the same cable from a PoE switch. Premises still wired for an old key system sometimes need a data cabling top-up, and we tell you that after we have looked, not before.
Handsets are the genuinely mixed answer. A current SIP desk phone — a supported Yealink, Cisco or Polycom, for instance — can usually be factory reset and re-provisioned onto the new system, so you keep the hardware and simply change what it points at. A digital handset built for a Panasonic, NEC or LG key system cannot: it speaks a protocol only its own box understands, and it retires with the box. Where phones can carry across, we say so. Where they can’t, we say that too, before you spend a cent.
What actually changes
The box on the wall stops being the phone system. On a hosted PBX there is nothing on site at all. On 3CX the system is software, which you can run in the cloud or keep on a server in your own comms room. Your lines change shape too: analogue and ISDN services are replaced by SIP trunks, which carry the same numbers over your internet connection and add or drop channels without anybody visiting the site.
Day to day, the change people actually notice is administration. Adding a staff member, changing after-hours routing, recording a new greeting or moving an extension to someone’s home office becomes a change in a browser rather than a booked service call. Calls follow people to a desk phone, a laptop or a mobile app on the same business number. And you get call reporting, which tends to be the first uncomfortable thing a new system reveals — most businesses have no idea how many calls they were missing.
3CX, hosted PBX or Microsoft Teams calling
Three sensible destinations, and the honest way to choose is to look at how your team already works rather than at a feature grid. We’re vendor-neutral, so we recommend the platform that suits how you work, not the one we’re tied to.
3CX suits businesses with real call traffic — a reception desk, queues, after-hours routing, more than one site — and it is licensed by simultaneous calls rather than per extension, so growing the team doesn’t blow out the bill. We’re a 3CX Partner, so where 3CX fits we install and support it properly. A hosted PBX suits businesses that want the features without owning anything: no server, no upgrades, nothing on site to fail. Microsoft Teams calling suits teams who already live in Teams all day — Direct Routing turns Teams into the phone system, and there is no SBC for you to deploy or manage.
If you would rather read the arguments than take ours, we have set them out in hosted vs on-premise PBX and 3CX vs Microsoft Teams, or you can compare the full range on the business phone systems hub.
Find your system
We have written a page for each of the systems we are asked about most often, covering what the situation means for that specific model and what the move looks like. Find yours below. For every end-of-support date gathered in one place, our legacy phone system replacement guide is the dated reference.
On-premise phone systems and key systems.
- Panasonic phone system replacement — the KX range, including the KX-NS1000, KX-NS700, KX-NS300, KX-TDE, KX-TDA and KX-NCP.
- Avaya IP Office replacement — IP Office and the IP500 V2. Avaya is still an active vendor here, so this one is about moving off an older release on your own terms rather than beating a shutdown.
- LG-Nortel Aria replacement — the LG-Nortel and LG-Ericsson Aria range: 24IP, 130, 300 and 600.
- iPECS eMG80 replacement — the Ericsson-LG eMG80, plus the older eMG800 and ipLDK.
- NEC PBX migration — the SL2100, SV9100, SV9500 and UNIVERGE 3C.
- Telstra DOT replacement — Digital Office Technology, which has a published shutdown date and no like-for-like Telstra successor at the same price point.
Cisco small-business UC appliances. All four are retired, with no firmware, bug fixes or security patches. For wider Cisco environments we also support and migrate Cisco IP PBX setups.
- Cisco UC320 replacement — the UC320W.
- Cisco UC520 replacement — the Smart Business Communications System.
- Cisco UC540 replacement — past its last order date, with hardware support long finished.
- Cisco UC560 replacement — the largest of the UC500 appliances, with its Last Date of Support long passed.
Handsets and adapters.
- Cisco SPA500 replacement — the SPA502G, SPA504G, SPA508G, SPA509G, SPA512G and SPA525G2.
- Cisco SPA112 replacement — the SPA112 and SPA122 analogue telephone adapters, often the last analogue device left in a building: a fax, a lift phone or an EFTPOS line.
- Yealink phone upgrade — the T19P, T20P, T21P, T22P, T41P, T42G, T46G and T48G. We’re an authorised Yealink reseller, so this one is a straight step up inside a brand you already run.
Routers and voice gateways. The gear underneath your phones counts too — once it stops getting security updates it becomes the weak point in an otherwise current setup.
- Cisco 800 series router replacement — the 880, 881, 886, 887, 891, 892 and C819.
- OneAccess router replacement — OneOS5-era OneAccess voice gateways, now under Ekinops.
What it costs, and what it saves
A replacement usually costs less to run than the system it replaces, because the money is in the lines rather than the hardware. Line rental on legacy services and per-minute call rates are where it goes, and our bill reviews have identified savings of up to 65%. Those are typical figures rather than a promise: your own bill decides your own number.
So the fastest route to a real figure is to send us a recent bill. We’ll show you what the replacement costs, what it saves and how long the payback takes, with no obligation. If we can’t save you money, we’ll tell you straight. Prefer to talk it through on site first? Book a review. And for the wider market view, we have broken down what a business phone system costs in Australia.
Who does the work
The same local team, start to finish. We audit what you have, design the replacement, port the numbers, provision the handsets, cut over around your trading hours and train your staff — most sites are live in days, not weeks. Installation and support is ours as well, so afterwards there is one number to call, answered by a real person in Greensborough rather than an offshore queue. Our team brings over 80 years of combined industry experience, and customers rate us 5.0 on Google.
Because we can also supply the business internet underneath the new system — with internet failover if calls can never drop — the connection is sized for voice from day one. One provider, one invoice, one number to call if anything ever goes wrong.
Real Connections. Real Easy.
Frequently asked questions
Will we have to change our phone numbers?
No. Your existing numbers move across through number porting, including 1300 and 1800 numbers, and they keep ringing throughout the switch. Nothing on your signage, website or vehicles has to change. Losing numbers is the most common fear about replacing a phone system, and it is the part we plan first.
Can we keep our existing desk phones?
Sometimes. A current SIP handset can usually be factory reset and re-provisioned onto the new system, so you keep the hardware. Digital handsets built for a Panasonic, NEC or LG key system can’t carry across, because they only speak to their own box. We go through your actual model list before quoting anything, and where phones can stay, they stay.
Do we need new cabling?
Usually not. If each desk already has a Cat5e or Cat6 data outlet, an IP phone plugs into the existing network and takes power over the same cable from a PoE switch. Premises still wired for an old key system sometimes need a top-up, which we confirm on a site walk rather than guess at over the phone.
How long does the changeover take, and will we miss calls?
Most replacements are live in days, not weeks. We build and test the new system alongside the old one, port the numbers on an agreed date and cut over around your trading hours so calls keep flowing. Staff are trained before the switch, not after it.
Our old system still works. Why replace it now?
Because working and supported are two different things. Once the maker stops issuing firmware and spare handsets only come from the used market, every fault turns into a scramble. Add the copper switch-off and most legacy systems have a deadline in their future — planning for it calmly costs far less than reacting to it.
What does replacing a business phone system cost?
It depends on your team size, your call volumes and the platform that fits, so the honest way to a real number is a free bill analysis. Send us a recent bill and we’ll show you the setup, the cost and the saving with no obligation. If we can’t save you money, we’ll tell you straight.
Can we replace it in stages instead of all at once?
Yes, and multi-site businesses often should. We can run the new system alongside the old one, move a site or a department at a time and keep calls flowing between the two while the changeover happens. It takes a little more coordination and removes most of the risk.
Do we have to move our internet to you as well?
No. A new phone system will run over the connection you already have, provided it has the headroom and handles voice properly. We check that and tell you honestly if it needs work. If you would rather have it all on one invoice we supply business internet too — but the phone system doesn’t depend on it.
We are moving premises soon. Should we replace before or after the move?
Before, in almost every case. Moving an ageing PBX means paying to re-cable and recommission hardware you are about to retire anyway. Plan the two together and the new system simply starts at the new address — see business relocation for how we sequence it.
Do you sell the brands you replace?
No. We’re vendor-neutral and we specialise in moving businesses off ageing systems, so we have no reason to steer you anywhere in particular. The exceptions are the ones we are accredited for: we’re a 3CX Partner and an authorised Yealink reseller, so where those suit you we supply them properly. Call 1300 747 266 and we’ll tell you what we would do.
Get a free bill analysis — and stop overpaying
Send us a recent phone or internet bill. We’ll show you exactly where the waste is — our bill reviews have identified savings of up to 65%.