BT VoIP Phone System Guide | Features, Pricing & Review

Nathan Hill-Haimes Technical Director 8 min read · Mar 2026

Why has BT moved its business lines to VoIP?

BT has spent several years migrating business customers off traditional PSTN and ISDN lines onto VoIP (Voice over IP — calls carried over your internet connection). The driver is the UK-wide PSTN switch-off, the retirement of the copper telephone network coordinated by Openreach. Once your exchange is migrated, line-based telephony stops working.

If you are weighing options now, start with the wider business VoIP market before signing anything, and understand the timeline behind the PSTN switch-off. The copper network is being retired across the UK, with Openreach managing the programme exchange by exchange (Openreach). Ofcom sets the consumer and business protections around that migration (Ofcom).

BT's answer to the post-PSTN world comes in two products. Picking the right one — or deciding BT is not the right supplier at all — depends on your headcount, your feature needs, and how much you value a single-supplier relationship.

What does BT Cloud Phone include and what does it cost?

BT Cloud Phone is BT's entry-level hosted VoIP system, aimed at small businesses with fewer than about 20 users. It gives you a cloud-based PBX with no on-site hardware, covering the core calling features most micro-businesses need. It is the closest BT equivalent to a standard small-business hosted phone system.

Core features

• Virtual receptionist (auto-attendant): greets callers and routes them to the right extension or department using voice prompts.
• Hunt groups: ring multiple extensions at once or in sequence so calls get answered.
• Voicemail to email: voicemail delivered as an audio attachment to chosen inboxes.
• Call recording: on higher tiers — useful for compliance, training, and dispute resolution.
• Mobile app: make and take business calls on iOS or Android using your business number.
• Call analytics: basic reporting on call volumes, answer rates, and missed calls.

BT Cloud Phone pricing

BT Cloud Phone is typically priced at around £15–£22 per user per month (typical UK 2026 market rates), depending on the tier and whether BT broadband is bundled in. IP desk phones add roughly £80–£200 per device upfront.

That sits at the higher end of the SME market. Comparable hosted systems from providers such as Gamma Horizon, 3CX, and bOnline offer equivalent functionality at around £8–£15 per user per month. For a five-user office on a two-year term, that gap compounds into real money.

What does BT Cloud Voice add for larger teams?

BT Cloud Voice is a more capable hosted telephony platform aimed at larger organisations. It runs on a wholesale carrier platform delivered through BT and its reseller partners, and adds scalability, advanced call management, and third-party integrations on top of the Cloud Phone feature set.

What you get over Cloud Phone

• CRM integrations: connects with Salesforce, Dynamics, and other CRM platforms to log calls and surface caller information.
• Advanced call analytics: detailed dashboards, wallboard displays, and call-centre statistics.
• SIP trunking: connect an existing on-premise PBX to BT's carrier network — the same principle covered in our guide to SIP trunking.
• Teams integration: some Cloud Voice versions support Microsoft Teams via direct routing, letting Teams act as the calling interface.

BT Cloud Voice pricing

BT Cloud Voice is usually sold on negotiated contracts. Indicative pricing is around £12–£25 per user per month (market rates as of 2026), depending on features, user count, and term length. Volume discounts exist, but the baseline still tends to run above independent VoIP providers.

What are the real pros and cons of a BT VoIP system?

BT's VoIP products work reliably and are backed by serious network infrastructure. The trade-off is price and contract rigidity. Here is the honest balance.

Advantages

• Managed by the UK's largest telecoms provider, with significant network capacity.
• One supplier for broadband and voice reduces administrative overhead.
• Well-defined support processes and escalation paths.
• Active PSTN migration management — BT handles the technical transition for existing lines.

Disadvantages

• Higher cost per user than most dedicated VoIP providers.
• 24-month contract terms with limited early-exit provisions.
• Feature development is slower than specialist VoIP platforms.
• Support quality for smaller accounts can be inconsistent.
• BT Cloud Phone's user cap can constrain a growing business.

How does BT VoIP compare to the alternatives?

The UK VoIP market is competitive, and BT rarely wins on price. The table below gives a broad comparison against the systems SMEs most often shortlist. All figures are indicative 2026 monthly prices per user and should be confirmed with each provider.

For most SMEs, an independent provider delivers better value than BT unless single-supplier convenience is a genuine priority. If your team already lives in Microsoft 365, native Microsoft Teams calling is usually the tighter, cheaper fit than bolting Teams onto BT's carrier network. Microsoft publishes Teams Phone licensing directly (Microsoft 365).

Some named market research supports the move off legacy lines: "Small businesses typically see 25–50% lower costs than traditional telephony after switching to VoIP" and "VoIP deployments save ~30 minutes per employee per day" (both Expert Market). Treat those as directional, not guaranteed.

Should you stay with BT or switch?

BT's VoIP products are not bad. They are reliable, professionally managed, and the migration path from legacy BT lines is straightforward. The hard part to justify is paying a premium for the BT brand when the market offers comparable quality for less — unless you have a specific commercial reason to consolidate with BT.

One factor buyers routinely underrate is security. A phone system is now an internet-connected application, which means it carries the same attack surface as any other cloud service. Whatever you choose, treat VoIP security as part of the decision, not an afterthought. As a security-first Microsoft partner, AMVIA assesses telephony the way we assess any other system on your network — one accountable provider, security considered first.

AMVIA compares VoIP options across the full UK market — including BT — to find the right system at the right price. If you want a like-for-like view of BT against the alternatives, our wider write-up on the BT phone system options is a good next read.