Quick answer
There is no single replacement for "an analogue line", because analogue lines do very different jobs. The only way to get this right is to work out what each line actually does and replace it accordingly: a voice line becomes a digital line or a hosted seat; a line feeding a phone system becomes SIP trunks; a line feeding an alarm becomes IP signalling; a lift line becomes a battery-backed mobile unit; a fax line usually just gets cancelled. This guide is the lookup table for that job.
The analogue line that has served your business for decades is being switched off on 31 January 2027, so the obvious question is what to replace it with. Most guides answer that as a product comparison - digital line versus hosted system versus keeping your PBX - and we have written that one too, in business landline alternatives. But it is the wrong first question. The right first question is what is this particular line for? Get that wrong and you will migrate your phones beautifully while a lift line and an alarm quietly stop reporting.
Step one: classify every line by what it does
Pull three months of bills, list every standing charge, then walk the building and match sockets to charges. For each line, decide which of these it is:
| Role | How to spot it |
|---|---|
| Voice line | A handset is plugged into it and people make calls |
| Voice line feeding a phone system | The line runs into a box in a cupboard, not a phone |
| Broadband carrier | Your ADSL or FTTC broadband rides on it |
| Alarm signalling | A phone cable runs to an intruder or fire alarm panel |
| Lift emergency line | A phone cable runs to a lift machine room or shaft |
| Card terminal | A phone cable runs from a PDQ terminal or its base |
| Fax | A fax machine is plugged into it |
| Door entry / gate intercom | The intercom dials a phone to release the door |
| Telemetry or plant monitoring | Something industrial that "phones home" |
| Unknown | Nobody can account for it |
The "unknown" row is normal and expected. In almost every audit we run, at least one line cannot immediately be explained. Some turn out to be genuinely redundant and cancelling them is an instant saving - which matters more now that legacy rental rose through 2026. Others turn out to be feeding something important. The rule is simple: investigate before you cease.
Step two: look up the replacement
| What the line does now | What replaces it | Who arranges it | Notes |
|---|---|---|---|
| Single voice line, one user | A digital voice line plugged into your router | Telecoms provider | Closest like-for-like. See Digital Voice explained |
| Several voice lines with hunting | Hosted phone system, sized on peak simultaneous calls | Telecoms provider | Usually cheaper and far more capable |
| Line(s) feeding an on-site PBX | SIP trunks into the same system | Telecoms provider | Keeps your handsets and call flows - see keeping your existing phone system |
| ISDN2 or ISDN30 | SIP trunks, or a hosted system | Telecoms provider | See ISDN replacement |
| Carrying your broadband | SoGEA, or full fibre if available | Telecoms provider | See SoGEA vs FTTP |
| Intruder or fire alarm signalling | Dual-path IP signalling (broadband plus mobile) | Your alarm company | Not a phone job. See alarm systems |
| Lift emergency phone | Battery-backed mobile (GSM) lift unit | Your lift company | Must work in a power cut. See lift lines |
| Card payment terminal | IP, WiFi or mobile terminal | Your card provider | Often free hardware - watch the contract. See card machines |
| Fax | Cloud fax to email, or cancel it | Telecoms provider, or nobody | Do the cost-per-fax sum first - see fax after the switch-off |
| Door entry / gate intercom | IP or mobile-based intercom | Manufacturer or installer | Check whether the panel supports it or needs replacing |
| Telecare, nurse call, warden call | Digital telecare equipment | Your telecare supplier | Never adapt analogue telecare onto a digital line. See care settings |
| Telemetry, plant or fridge alarms | IP or mobile module | Equipment supplier | Ask the maintainer; do not assume |
| Unknown | Investigate | You | Do not cease it |
The column that matters most is the third one. Four of these replacements are not your telecoms provider's job, and no provider's migration plan will include them. If you tell only your phone company that you are migrating, the alarm, the lift, the card terminal and the telecare will not be dealt with.
Step three: sequence it by lead time, not by importance
Everything on that table has a different lead time, and the order that works is counter-intuitive - you start with the things that finish last.
- This week: phone the alarm company, the lift company and any telecare supplier. Four to twelve weeks is normal for their work and it is getting longer, so these calls set your whole timeline.
- This week: check what connectivity your address can get, and order it. Two to six weeks for SoGEA or FTTP; considerably longer for a leased line.
- Then decide the voice replacement. This is genuinely quick, which is why it should not go first.
- Then plan the porting of every number and DDI range.
- Then sort power resilience - battery backup and call diversion.
- Cut over, test everything, and only then cease the old lines.
Our switch-off deadline guide has the full timeline, and the switch-off checklist is the working version to tick off.
If you would like this done for you - the audit, the availability check, the replacement pricing and the coordination around your other suppliers' dates - get a no-obligation quote.
What every replacement has in common
Whatever each line becomes, three things are now true that were not before:
It depends on your internet connection. The connection stops being an IT purchase and becomes part of your phone system, your alarm path and possibly your card payments. It needs headroom and it needs voice traffic prioritised - see internet speed for VoIP.
It depends on mains power. Analogue copper carried its own power from the exchange; nothing that replaces it does. A UPS on the router plus automatic diversion of calls to mobiles covers most scenarios, and anything safety-critical needs its own battery-backed solution. See landline resilience and failover.
Several things now share one failure point. Once phones, alarm signalling and card payments all ride on one broadband connection, a single fault takes out three services. That is the argument for 4G or 5G failover, and it is a stronger argument than it was when the connection only carried email.
Your numbers are the part that does not change
Worth repeating because it is the thing people worry about most and need to worry about least. Geographic numbers, non-geographic numbers and full DDI ranges all port to the new service unchanged. Porting is scheduled work taking a couple of weeks to arrange, so build it into the plan rather than leaving it to the end - and the one hard rule is never cease the old line before the number has moved. See keeping your business landline number.
Choosing the voice product itself
Once you know which lines are voice lines and how many simultaneous calls you need, the product decision is a separate and much easier question: a single digital line, a hosted phone system, SIP trunks into your existing system, Teams calling, or a fixed number diverting to a mobile. We compare all five, with prices and a decision table, in business landline alternatives.
The bottom line
"What replaces an analogue line?" has no single answer, because your analogue lines are doing at least four different jobs. Classify each one by role, look up its replacement, and notice how many of those replacements belong to somebody other than your phone provider. Then sequence the work by lead time - alarm, lift and telecare first, phones last - and you will find the phone part was never the hard bit.
Want a hand? Get a no-obligation quote or call 0333 006 9399, and we will audit your lines and tell you what each one is for before we quote anything.
Getting unknown calls on a business line? Our free UK phone number checker shows which network or provider Ofcom allocated any number to, and whether the range is in service — no sign-up.
Frequently asked questions
What replaces an analogue phone line?
It depends entirely on what the line does. A voice line becomes a digital line or a hosted phone seat; a line feeding a phone system becomes SIP trunks; a line carrying broadband becomes SoGEA or full fibre; an alarm line becomes IP signalling; a lift line becomes a battery-backed mobile unit; a fax line usually just gets cancelled.
How do I find out what each of my phone lines does?
List every standing charge on three months of bills, then walk the building matching sockets to those charges. Look specifically for phone cables running to things that are not phones - alarm panels, lift machine rooms, card terminals, door entry boxes and fax machines. Anything you cannot account for should be marked unknown and investigated.
Can I replace an analogue line with just one digital line?
If the line is purely a voice line used by one person, yes - a digital voice line is the closest like-for-like and plugs into your router. If the line is doing anything else, or if more than one person needs to answer, a single digital line is the wrong replacement.
Do I need to replace all my analogue lines at once?
No, and often you should not. Sequence the work by lead time: alarm, lift and telecare replacements take four to twelve weeks and depend on third-party engineers, so start those first. Voice lines can be migrated quickly, so they go later. Everything must be done before 31 January 2027.
What about alarms, lifts and card machines on analogue lines?
Each needs its own migration arranged with the company that maintains it - your alarm company, your lift maintenance company and your card provider respectively. No telecoms provider's migration includes them, and adapters are not a safe answer for anything safety-critical. These carry the longest lead times, so make those calls first.
Do I lose my number when I replace an analogue line?
No. Your existing numbers, including non-geographic numbers and full DDI ranges, port to the new service and customers carry on dialling the same number. Porting takes a couple of weeks to arrange, and the old line must not be ceased until the number has moved.
What is the simplest analogue line replacement?
For a single basic voice line, a digital voice line - the handset plugs into your router and behaves much as before. Just remember it needs internet and mains power, unlike old copper, so plan battery backup or call diversion if you need the phone to work during an outage.