For twenty years, “VoIP vs landline” was a genuine debate with genuine trade-offs. In 2026 it is something rarer: a comparison with an expiry date printed on it. The UK’s analogue phone network (the PSTN, the copper system behind every traditional landline) is in its final months of withdrawal, with remaining lines switched off by the end of January 2027. Businesses are not choosing between VoIP and landline anymore; they are choosing between migrating on their own schedule or on Openreach’s.
So this page does two jobs: the honest comparison, for completeness and for anyone weighing *how much* VoIP to adopt, and the practical part that now matters more: what replacing your landlines actually involves, costs, and breaks if you leave it late.
The comparison, for the record
What landlines did well: simplicity, familiarity, independence from your internet connection, and power from the exchange (an old analogue phone worked in a power cut). Those were real advantages, and the last two still deserve planning attention in the replacement, as we cover below.
What VoIP does better, now that call quality parity arrived years ago: cost (no line rental per physical line, cheaper calls, one system across sites), flexibility (your number rings desk, laptop and mobile; staff work anywhere; capacity scales in minutes), features that used to cost PBX money (routing, queues, voicemail-to-email, call recording, analytics), and continuity (an office flood diverts calls to mobiles instead of ringing into a wet building). The full mechanics are in our cloud telephony explainer.
The honest dependency: VoIP quality is internet and network quality. Businesses with poor broadband or congested networks experience VoIP badly and blame the technology; the fix is connectivity and QoS engineering, not nostalgia for copper. This dependency is the one legitimate reason to sequence (fix the line first), never a reason to keep the landline, which is leaving regardless.
What the switch-off actually means for you
Three practical consequences, in rising order of surprise:
- Your phone lines are moving whether you act or not. Providers are migrating customers ahead of the deadline; the choice you retain is whether the migration is a planned upgrade to a system you chose, or a default conversion to whatever your current provider ships laggards.
- The number is not the line. Your established numbers port to the new system and behave identically for callers; the fear of “losing our number” is the most common and least justified migration worry.
- The quiet dependents are the real deadline risk. It was never just phones on those copper lines: alarm systems, door entry, lift phones, card terminals, fax-dependent processes and monitoring dialers frequently ride analogue lines, and each needs an IP-era replacement or adapter *identified before* the line dies, not after. This inventory is the single most valuable hour of switch-off preparation, and the one businesses skip.
Costs compared
The economics generally favour the forced move, which is some consolation:
- What you stop paying: line rental per analogue line (each one a standing charge), call charges at legacy rates, and the maintenance contract on the ageing PBX in the cupboard, plus its eventual replacement.
- What you start paying: per-user VoIP subscriptions (typically £5 to £20 per user monthly with bundled calls), optional IP handsets (many businesses go headset-and-app for most staff), and possibly a broadband upgrade if the audit says so.
For a typical 10-person office running two or three analogue lines and an old PBX, the monthly totals usually land close to even or slightly better on VoIP, with the feature gap and the removed PBX-replacement liability as the actual gain. The business phone system cost guide prices worked examples.
Migrating without drama
The sequence we run, sized for SMEs:
- Audit: lines, numbers, the PBX, and above all the quiet dependents (alarms, entry systems, terminals): what exists, what it rides on, what replaces it.
- Connectivity check: does the current line carry your call volume with headroom, and is failover in place so phones survive an internet blip? Fix first if not.
- Choose the platform: dedicated hosted VoIP or Teams Phone for Microsoft-centric teams, with routing and hours designed rather than defaulted.
- Port and parallel-run: numbers ported on a scheduled date, old and new briefly overlapping, so callers never hit a gap.
- Retire the copper: lines ceased (stop paying rental the month they die), PBX decommissioned, dependents confirmed on their new arrangements.
Weeks end to end, dominated by porting lead times, with the golden rule being simply: start while the deadline is still measured in months.
Frequently asked questions
Are landlines really being switched off in the UK?
Yes: the analogue PSTN is being withdrawn, with remaining traditional lines switched off by the end of January 2027. Phone service continues, delivered digitally; the copper-line era ends.
Can we keep our business phone number when switching to VoIP?
Yes: number porting is standard and regulated, covering geographic (01/02), 03 and 08 numbers. Callers notice nothing; the schedule is planned so there is no gap.
Is VoIP cheaper than a landline for business?
Usually modestly cheaper month to month once line rentals and PBX maintenance stop, and substantially better per pound given the feature and flexibility gap. The exact answer depends on your line count and call patterns; the audit prices it.
What happens to VoIP phones if the internet goes down?
Configured properly, calls fail over automatically to mobiles or another site and callers notice nothing; unconfigured, they hit voicemail. Failover design (and battery consideration for anything critical, since digital phones need power) belongs in the migration plan, replacing the old exchange-powered resilience deliberately rather than losing it accidentally.
What about our alarm line and card terminals?
Exactly the right question: analogue-dependent devices (alarms, door entry, lifts, some terminals) need IP-native replacements or adapters, arranged with their providers before the line goes. The audit exists mostly to catch these.
Should we wait until closer to the deadline?
No: porting lead times, dependent-device replacements and engineer availability all worsen as the deadline concentrates demand. Migrating on your schedule is cheaper and calmer than migrating on the network’s.
Book the audit before the letter arrives
Every business with analogue lines gets the migration; the only variable is how orderly it is. Our free IT health check includes the line-and-dependents audit, a connectivity check with your call volumes in mind, and a priced migration plan through our cloud telephony service. Get in touch while January 2027 is still comfortably far away.
