Business VoIP and phone system providers.
UK-based, contract-free cloud PBX with the broadest feature set at its price point, and one of the very few phone platforms with a real REST API, webhooks and a native MCP server.
Month-to-month (entry plan): $6/moAnnual commit, per month: Same priceMonthly premium: 0%
The obvious phone system if you already live in Microsoft 365: cheap on paper, with the real cost hiding in licence stacking and the PSTN route you choose.
Month-to-month (entry plan): £9.24/moAnnual commit, per month: £7.70/moMonthly premium: 20%
French-built cloud phone with unlimited calling to 110 destinations and all data hosted in France: the EU-sovereign pick, on a 12-month commitment.
Month-to-month (entry plan): £24/moAnnual commit, per month: £15/moMonthly premium: 41%
Cheapest published UK entry price and a unique eSIM business-mobile bundle, under an Ericsson owner still working out what to do with it.
Month-to-month (entry plan): Not publishedAnnual commit, per month: £10/moMinimum commitment: £120
The cheapest big-brand unlimited UK calling plan, bolted onto Zoom Workplace, with no UK data-residency region and the worst Trustpilot score in this comparison.
Month-to-month (entry plan): £8/moAnnual commit, per month: Same priceMonthly premium: 0%
Enterprise UC and contact centre on one platform with a financially backed five-nines SLA, sold on quote, on contract, and with a poor support record on Trustpilot.
Month-to-month (entry plan): Not publishedAnnual commit, per month: £22/moMinimum commitment: £264
Software PBX licensed per simultaneous call, self-hosted or hosted by 3CX: cheap per seat at scale, sold only through partners who increasingly describe it as hard to work with.
Month-to-month (entry plan): Annual onlyAnnual commit, per month: £330/yrMinimum commitment: £330
The free, open-source PBX on Asterisk: total control and zero licence cost, in exchange for owning security, patching and every integration yourself.
Month-to-month (entry plan): FreeAnnual commit, per month: FreeMinimum commitment: Free
SMB PBX sold as appliance, software or cloud edition through channel partners: solid and well-supported in the UK, but an infrastructure product rather than a cloud-native platform.
Month-to-month (entry plan): Annual onlyAnnual commit, per month: $399/yrMinimum commitment: $399
CRM-first cloud call centre with excellent integrations and a headline price that bears little relation to what you actually pay once minimums, annual terms and add-ons stack up.
Month-to-month (entry plan): $40/moAnnual commit, per month: $30/moMonthly premium: 33%
The most feature-laden UCaaS on the market, and the one most UK buyers will pay too much for, on US-centric bundles with the worst contract reputation in this comparison.
Month-to-month (entry plan): $30/moAnnual commit, per month: $20/moMonthly premium: 50%
Enterprise hybrid PBX from a vendor that went through Chapter 11 in 2025 and shut its own cloud service in 2026: the legacy option, for estates that already own it.
Month-to-month (entry plan): QuoteAnnual commit, per month: QuoteMin seats: 5