What Is UCaaS? 7 UK Providers and Costs Compared (2026)

UCaaS, short for unified communications as a service, is a cloud subscription that puts business calls, video meetings and team messaging in one app. For UK businesses with 20 to 500 staff, published UCaaS plans run from £12 to £20 per user per month. We compared 7 UCaaS providers in the UK. RingCentral is the highest rated we have reviewed, at 8.4/10, but Microsoft Teams Phone is the better buy if your staff already work inside Teams.

This guide is for the person who has to make the decision: what UCaaS is, when it beats a PBX with SIP trunks, what 20, 50 and 100 seats cost, and how to move your numbers without losing calls. All prices exclude VAT and come from each provider’s own UK pricing page, read in October 2026.

What Is UCaaS?

UCaaS is a phone system, video meeting tool and messaging app delivered as one cloud service, paid per user per month. There is no PBX box to maintain. Staff use one app on a laptop, a mobile or a desk phone, and the provider runs the platform, the updates and the call routing.

The practical gain is fewer contracts. A business paying separately for a phone system, a meeting tool and a chat tool can move all three onto one bill and one admin portal. The trade-off is that you depend on your internet connection and on one vendor, so a UCaaS decision is harder to reverse than swapping a VoIP line.

UCaaS vs VoIP, CCaaS and CPaaS: What Is the Difference?

These four terms get mixed up in sales calls, and the difference decides what you buy. VoIP is the technology, and UCaaS is a product built on it.

Zoom Phone and Microsoft Teams Phone both count as UCaaS once they sit alongside the meetings and chat in the same platform. A standalone VoIP line with no shared meetings or messaging does not.

UCaaS Providers UK Compared

The best UCaaS provider in the UK depends on what you already run. RingCentral suits a business with no fixed platform, Teams Phone and Zoom Phone suit businesses already on those tools, and 8×8 and GoTo Connect need a quote. Ratings are from our published reviews, and a provider without a review has none.

RingCentral is the most complete single platform here, and our highest-rated UCaaS provider at 8.4/10. Premium adds automatic call recording, single sign-on, CRM links and whisper and barge tools, which is the plan most mid-sized buyers end up on.

Pricing depends on seat count. Premium costs £18.99 per user per month for 20 to 99 users and £17.99 at 100 or more, on annual billing. Standard costs £13.99 and £12.99 at the same bands, with 750 outbound minutes per user and manual recording only. Essentials is not sold at 20 users or above, so ignore any “from £7.99” headline. You can add unlimited calling across its EMEA zone once you reach 20 users.

Customer reviews are the weak spot. RingCentral scores 3.2 out of 5 on Trustpilot from 680 reviews, and 26% of them are one-star. Check the support route and the contract exit before you sign.

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Teams Phone adds a phone system to the Teams app your staff already open every morning. It is usually the cheapest way to add calling to Microsoft 365, and the one with the least staff training. We have not yet published a full review, so it carries no rating here.

Microsoft sells it in four UK versions on annual billing. Teams Phone Standard costs £7.70 per user per month with no calling included. Adding metered calling takes it to £9.20. Domestic calling, with 3,000 outbound UK minutes, costs £13.10. Domestic and international costs £26.10. Every version needs a separate Microsoft Teams licence, which our table leaves out.

You can also keep Teams as the app and buy calls from a carrier, through Operator Connect or Direct Routing. That suits a business with existing SIP contracts, but it adds a partner and more set-up. Ask your Microsoft partner to confirm automatic recording and sign-in requirements, because Microsoft’s pricing page does not state them.

Zoom Phone is a strong value option for a business that already meets on Zoom. It has unlimited UK calling, call recording, supervisor tools and UK SMS on published plans. We have not yet published a full review, so it carries no rating here.

On Zoom’s UK plans, UK & IRL Unlimited costs £12.80 per user per month on annual billing, and a metered version costs £8.40. Both add phone to Workplace Basic, which limits meetings to 40 minutes. Pro Plus costs £15.90 and extends meetings to 30 hours. Business Plus costs £19.60, adding 300-person meetings, single sign-on and managed domains.

Check the licence count. Zoom lists Unlimited and Pro Plus at 1 to 99 licences and Business Plus at 1 to 250. A larger rollout will need a sales conversation, so budget from a quote.

Dialpad builds AI into the base product, so real-time transcripts and AI call summaries come with every Connect plan. That makes it a good fit for sales and account teams who dislike typing up calls. We rate it 7.5/10, and it scores 4.1 out of 5 on Trustpilot from 3,196 reviews.

In GBP, Standard costs £12 per user per month on annual billing or £22 monthly. Pro costs £20 annual or £28 monthly, and adds CRM integrations and 24/7 support. Single sign-on needs the Enterprise plan, which has no published price, so a business that insists on SSO should treat Dialpad as quote-based.

8×8 is worth a quote if you call abroad a lot or expect to add a contact centre later. Its X Series uses the same platform for both, but it publishes no UK prices, so we cannot show a seat-count cost. We have not yet published a full review, so it carries no rating here.

On its Ireland X Series page, X2 includes unlimited calling to 14 countries and X4 extends that to 47 in total, with barge, monitor and whisper tools. Those are not UK terms. Ask for them in writing, and confirm which countries and contract length apply to your quote.

GoTo Connect suits a business with regular calls to landlines abroad. It includes calls to 50 or more countries, unlimited auto attendants, call recording and video for 250 participants on all plans, according to GoTo. We rate it 7.5/10.

GoTo publishes no UK prices, so every figure must come from a quote. The international calling covers landlines only, so calls to mobiles are charged per minute. CRM integrations may need the CX plan, and GoTo has no public free trial, so ask for a pilot before you commit.

Vonage has the simplest published UK price list, and the Max plan is unusual because it adds an eSIM and a business mobile number. We rate it 7.0/10, and it scores 4.6 out of 5 on Trustpilot from 3,259 reviews.

Express costs £10 per user per month with metered outbound calls. Core costs £15 with unlimited UK calls, CRM links and Teams compatibility. Max costs £25. Core does not include recording, and the Pro plan has no published UK price, so recording needs a quote. Standard support runs 8am to 8pm on weekdays, and 24/7 cover is limited to accounts of 500 users or more, which matters if your phones are customer-facing.

How Much Does UCaaS Cost at 20, 50 and 100 Seats?

UCaaS costs from about £240 to £400 a month for 20 seats on published plans, and from about £1,200 to £2,000 for 100 seats. These figures use the correct price band for each seat count, on annual billing and excluding VAT.

Cheapest does not mean like for like. Most businesses in this size range want automatic recording, single sign-on and CRM links, and that spec moves the order. RingCentral Premium and Zoom Business Plus meet it at list price. Dialpad needs Enterprise for SSO, and Vonage needs its unpriced Pro plan for recording, so both become quotes.

When Does UCaaS Beat a PBX Plus SIP Trunks?

UCaaS beats a PBX with SIP trunks when you want calling, video and messaging on one bill and have no reason to keep hardware. A PBX with SIP trunks still wins when you have recent kit, a long contract or specialist integrations to protect.

If you are keeping hardware, start with our guide to PBX telephone systems and our SIP trunk provider comparison. If you still have analogue or ISDN lines, the date matters, and our PSTN switch-off guide covers the steps. GOV.UK says all Openreach PSTN users must move by 31 January 2027, and Openreach lists ISDN systems, payment terminals and security alarms among the kit that will stop working.

How Do You Migrate to UCaaS and Port Your Numbers?

Moving to UCaaS works best in stages: audit what you have, test your network, pilot with one team, then port numbers site by site. Keep your old lines live until calls are proven on the new platform, and agree a dated porting plan with the provider before you give notice.

1. List every number and line. Include fax lines, alarms, lift phones, card terminals and any number printed on your vehicles.
2. Check your contract end dates. Find notice periods and exit fees on your current lines before you set a go-live date.
3. Test the network at a busy time. Run a trial during peak hours, on the same connection your staff will use.
4. Pilot with one team. Pick staff with real call volume and rebuild their call flows, queues and voicemail first.
5. Get a dated port in writing. Ask who raises the request, what the port costs and what happens if it fails.
6. Port one site at a time. Keep a rollback route, and avoid your busiest trading days.
7. Cancel old services last. Do this only after inbound calls reach the right people on every ported number.

What UK Compliance Checks Apply to UCaaS Call Recording?

UK businesses can record calls for defined purposes, but they must tell users of the system and handle recordings as personal data. Before you buy UCaaS, confirm where recordings are stored, how long they are kept, and who can access them.

The Investigatory Powers (Interception by Businesses etc. for Monitoring and Record-keeping Purposes) Regulations 2018 allow interception for purposes such as establishing facts, checking regulatory compliance and assessing staff standards. The business must make all reasonable efforts to inform everyone who may use the system. UK GDPR then applies to what you keep. Our business call recording guide covers the practical set-up.

• Storage location: ask which country holds recordings and backups, and get it in the contract.
• Retention: set a period that fits your purpose, and check the platform can delete on schedule.
• Card payments: make sure recordings do not capture card details, and ask how the platform pauses recording.
• Regulated firms: FCA firms should check SYSC 10A with their compliance lead before choosing a plan.
• Certifications: ask for current evidence. RingCentral lists SOC 2, PCI DSS and Cyber Essentials Plus, and GoTo lists SOC 2 and ISO 27001.

Which UCaaS Route Works Best With Microsoft Teams?

If your staff live in Teams, you have three UCaaS routes: buy Microsoft Calling Plans, connect a carrier to Teams Phone, or run another UCaaS platform with a Teams integration. The first is simplest, the second keeps your carrier, and the third suits businesses wanting features Teams lacks.

Which UCaaS Provider Should You Choose?

Choose your UCaaS provider by starting with the platform your staff already use, then checking spec and seat count. RingCentral is our pick when nothing else is decided, but several common situations point elsewhere, and a good quote process will show that quickly.

• Choose Teams Phone if you already pay for Microsoft Teams and want calling in the same app.
• Choose Zoom Phone if your business already meets on Zoom and you want UK SMS and unlimited UK calls.
• Choose RingCentral if you have no fixed platform and want recording, SSO and CRM links in one published plan.
• Choose Dialpad if transcripts and call summaries matter more than SSO.
• Get quotes from 8×8 and GoTo Connect if a large share of your calls go overseas.
• Choose Vonage if your staff are mostly on mobiles, or if a CRM link matters more than recording at the entry price.

Businesses with mainly phone-based customer service should compare a contact centre platform as well, since UCaaS queues can run out of road at higher agent counts. If you only need cheap lines for a small team, our business phone systems hub has simpler options.

How We Compared These UCaaS Providers

We compared 7 UCaaS providers using each provider’s own UK pricing page, clicking through seat bands, billing options and plans in October 2026. Where a provider publishes no UK price, we say so and show no estimate. We assessed fit for businesses of roughly 20 to 500 staff: published pricing, recording, single sign-on, Teams links and support hours.

Ratings come from our published reviews, and we give no rating to a provider we have not reviewed. Commercial relationships do not set the order or the verdicts. Prices change often, so confirm them in a written quote.

Last updated: October 2026. Prices exclude VAT and were checked against provider websites on 30 and 31 October 2026.

Emma Clarke

Technology & Payments Specialist

Emma covers the full range of business technology, including EPOS systems, merchant accounts, telecoms, and web tools. Her experience as a retail systems consultant helps businesses choose the right digital solutions to improve efficiency and sales.

Reviewed by

Sarah Mitchell

B2B Commerce & Finance Reviewer