Current position (last reviewed: 15 July 2026): UK dental practices still on Openreach’s legacy analogue landline network—the Public Switched Telephone Network (PSTN)—need to move to modern digital (all-IP / VoIP) services by 31 January 2027. That date is stated on the GOV.UK telecommunications modernisation timeline and aligned with Openreach and BT Business guidance. Dates can be updated by operators—re-check primary sources before you commit capital.
Direct answer: Treat PSTN/WLR migration as a telephony continuity project. Treat an AI receptionist as an optional service layer on top of working call delivery. You may need VoIP because copper is ending; you may add AI because you want overflow booking—those decisions overlap but are not the same purchase.
This guide is for UK dental practices and groups. Architecture choices (keep vs migrate phones) are expanded in AI vs traditional clinic phone systems. Continuity design: healthcare call-handling resilience. Conversational delay / provider questions: latency and phone-migration myths.
Plain English: what is switching off?
| Term | Meaning |
|---|---|
| PSTN | The old public analogue telephone network that carried traditional landlines. |
| WLR (Wholesale Line Rental) | The umbrella for many Openreach products that rely on that legacy copper network (how many “traditional lines” are wholesaled to phone companies). |
| ISDN | An older digital-on-copper business line technology also being withdrawn with the legacy estate. |
| ADSL | Broadband that piggybacks on traditional copper phone lines—also in scope of the legacy switch-off for many customers. |
| All-IP / VoIP | Voice delivered as data over an internet Protocol network (your broadband or a dedicated IP access)—the replacement model. |
What changes for a practice: calls no longer depend on copper analogue signalling in the old way. Voice rides on IP access. Devices that quietly used the copper pair—some alarms, payment terminals, door entry, lift lines, fax—may stop working unless upgraded or replaced. BT Business lists examples such as alarms, EPOS, door entry, CCTV and fax, and notes broadband on traditional lines may need upgrading.
Industry context (not a second deadline): migration was previously associated with an earlier industry target (often discussed as end-2025) and later moved; the operative migration date for Openreach PSTN users in current GOV.UK/operator material is 31 January 2027. Openreach has also described wholesale price rises on remaining legacy WLR products during 2026 to encourage migration—ask your supplier what you are paying today.
If you do nothing: BT Business states some customers may be moved via a Protective Migrations programme to a basic IP solution (with notice), while services such as ISDN, Featureline, multiline and certain broadband accesses cannot be auto-moved and stop working from 31 January 2027 if not migrated. Do not assume you are in the auto-migrate cohort—ask your provider in writing.
Migration checklist for dental practices
Work with your current communications provider (and device vendors). Openreach’s public advice to businesses is essentially: review → test → switch.
- Supplier clarity — Who provides your voice and broadband today? Get a written list of services still on PSTN/WLR/ISDN/ADSL.
- Lines and numbers — Main published number, direct dials, fax lines, multi-line groups. Confirm you can keep/port numbers on the new IP service.
- Broadband / access — Is voice quality dependent on fibre (e.g. FTTP) or SOGEA-class access? Size bandwidth for concurrent calls + clinical cloud apps.
- Resilience — Second access path, 4G/5G failover, or divert-to-mobile plan (see outage section).
- Non-voice devices — Alarms, payment terminals, door entry, CCTV, lift lines, franking/fax where still used—confirm IP-compatible replacements with each vendor.
- Call routing — Queues, open/closed hours, overflow to second desk or mobile, multi-site hunt groups.
- Recording / compliance — If you record calls, rebuild notice, storage and access on the new platform.
- Continuity plan — What happens on cutover morning if something fails?
- Testing — Inbound/outbound, number presentation, payment terminal auth, alarm signalling, lift line if applicable.
- Staff briefing — New handsets/apps, how to transfer, who escalates telecoms faults.
Optional later step: add AI overflow/OOH once the dial tone path is stable.
AI reception and VoIP migration are separate decisions
| Decision | Question it answers | Typical trigger |
|---|---|---|
| Migrate off PSTN | Will our lines and copper-dependent devices still work after Jan 2027? | Analogue/WLR/ISDN still in use |
| Choose VoIP features | Do we need better queues, multi-site routing, recording, apps? | Ops design / group standardisation |
| Add AI receptionist | Should software handle approved intents (FAQs, bookings) on overflow/OOH? | Missed calls, after-hours demand |
You can:
- migrate to VoIP without AI
- add AI on existing business VoIP via routing/overflow (when the path supports it)
- migrate telephony and add AI in one programme—but budget and test them as two workstreams
Avoid buying “AI” as a substitute for a broken copper migration plan.
How Clero connects (verified, non-absolute)
Clero is a conversational AI reception layer. In practice, calls are delivered by your telephony path into the voice agent (commonly via your business VoIP / partner routing). Clero’s product booking connectors are separate again (e.g. Dentally, CareStack, Semble, Aerona and Exact (via Exact Online Booking when enabled) where configured.
Accurate claims:
- Many practices keep their published number and route or overflow selected calls into AI.
- A full provider swap is not automatically required solely to try AI—if you already have workable IP voice and routing.
- Practices still on analogue/PSTN may need a digital voice migration anyway because of the 2027 withdrawal—independent of Clero.
- Partner offerings such as Dental VoIP Connect / The VoIP Shop are one telephony option some clinics use alongside Clero; they are not a mandatory lock-in to use the AI layer.
Remove absolute marketing: “no phone migration ever required” is too strong for UK clinics still on copper or with unsupported routing. Prefer: *migration depends on your current lines and routing controls*.
Also removed from older versions of this page: invented missed-call £ figures, “0% abandonment,” unrestricted SOE/Pearl screen-pop write-back claims, and silent cross-site load-balancing as switch-off benefits.
Outage and resilience (power + internet)
Digital voice usually needs:
- Mains power for routers, ONTs, PoE switches and handsets (unless battery-backed)
- Working internet / IP access for call signalling and media
Design for failure:
- UPS on the network stack for short cuts
- mobile or secondary broadband failover where proportionate
- documented divert to mobiles / another site if the surgery WAN dies
- test the failover path quarterly
- do not treat AI alone as the continuity plan—if telephony cannot deliver the call, nothing answers
Resilience patterns for clinics: call-handling resilience guide.
Practical timeline (illustrative)
| When | Action |
|---|---|
| Now | Inventory lines/devices; ask supplier if you are on PSTN/WLR/ISDN/ADSL |
| This quarter | Choose IP voice path; schedule non-voice device upgrades |
| Before cutover | Port/test numbers; train staff; write failover |
| Before 31 Jan 2027 | Complete migration; confirm nothing critical remains on copper |
| After stable dial tone | Optionally pilot AI overflow/OOH with booking rules |
Frequently asked questions
When is the switch-off?
31 January 2027 for Openreach PSTN migration per current GOV.UK timeline; confirm with your supplier.
Must we change provider to add AI?
Not always—if IP voice and routing already work. Copper retirement may still force a digital migration.
Keep our number?
Usually yes via keep/port—confirm with the provider.
What else breaks?
Devices on traditional lines (alarms, terminals, etc.) and some copper broadband—inventory everything.
Power cuts?
Plan backup power and divert paths; VoIP is not copper-powered like old exchange lines.
Is partner VoIP required for Clero?
No—optional telephony path; AI is a separate layer.
Migrate early enough to test devices and failover—not in the last week of January 2027. Use primary operator notices for your account, then decide whether AI belongs on the new (or existing) IP path.