Business Phone Systems · Comparison
8x8 vs 3CX vs Gamma vs Avaya vs Microsoft Teams vs AWS: which one actually fits your team
Short answer: none of them are interchangeable, and most businesses are on the wrong one simply because nobody laid the six out side by side before the contract got signed. Here is that comparison, plus a tool so you can check your own.
Compare any two side by side
Pick your current provider on one side and whatever you are considering on the other. The table covers calling, meetings, contact centre, integrations, security and pricing, and flags every row where the two disagree.
Business Communications
Feature Comparison
Compare 8x8, 3CX, Gamma, Avaya Cloud Office (RingCentral), Microsoft Teams and AWS (Amazon Connect) side by side. Pick two platforms below, or swap them instantly.
Want us to run this against what you are actually paying right now? Send your current bill across and we'll mark up exactly where it sits against the other five. No obligation.
Get my free comparisonIf you asked six salespeople which business phone system is best, you would get six different answers, and all of them would be partly right. 8x8, 3CX, Gamma, Avaya Cloud Office, Microsoft Teams and AWS Amazon Connect are not competing to do the same job. Some are phone systems with contact centre features bolted on. One is not a phone system at all. Picking between them properly means knowing which category you actually need, not which one had the best pitch.
Why this comparison, and why now
Research published by Flexera this year put wasted UK business software spend at close to one pound in every five, mostly licences nobody uses any more or duplicated tools nobody spotted. Finance teams have started auditing that spend properly. Phone contracts have mostly escaped, because fixed seat counts and twelve-month terms were simply how the industry worked and there was nothing to hold them against.
That changed a few weeks ago. 8x8 dropped both the fixed seat count and the annual term from its pricing for UK businesses under 100 users, moving to pay-as-you-go instead. It is the first time one of the major providers has priced business calling this differently, and it makes a decent stress test for whatever you are currently signed up to.
None of the other five work the way 8x8 now does, and they don't work the same way as each other either. Teams sells its calling add-on separately from a Microsoft 365 seat following the EU's antitrust ruling. Gamma prices mostly through resellers on UK-specific terms. 3CX charges per simultaneous call rather than per user, which changes the maths completely depending on your team's shape. That is the whole reason to compare them properly rather than renew on autopilot.
The six systems, in one line each
8x8
UCaaS with contact centre built in. Best for hybrid or remote teams that want calling and customer service in one platform. Full 8x8 breakdown →
3CX
Self-managed PBX software, priced by simultaneous calls rather than seats. Best for cost-conscious SMBs happy to run their own system. Full 3CX breakdown →
Gamma
UK cloud telephony and SIP, and one of the biggest Teams Direct Routing providers going. Best for UK-only businesses already on Teams. Full Gamma breakdown →
Avaya Cloud Office
RingCentral infrastructure sold under the Avaya name. Best for existing Avaya customers moving to the cloud. Full Avaya breakdown →
Microsoft Teams
Collaboration suite first, phone system second, and calling is now a separate add-on. Best for businesses standardised on Microsoft 365 who don't need a full contact centre. Full Microsoft Teams breakdown →
AWS Amazon Connect
Not a phone system. A usage-priced contact centre platform for enterprises building something custom on top of what they already have. Full AWS breakdown →
What actually matters in each category
Calling and everyday use
If your team lives on the phone, this is the category that matters most and the one people check least. 3CX and Gamma both keep call recording and auto attendant simple and included. 8x8 goes further on recording retention, up to ten years on its higher plans, which matters if you are in a regulated sector. Amazon Connect has no office voicemail at all, because it isn't trying to be an office phone system.
Meetings and video
Teams wins this outright, it is built for it. 8x8 and Avaya both hold their own with decent participant limits. Gamma leans on Webex rather than its own video product. 3CX has video built in but no whiteboard. None of this matters if your team barely uses video, which is worth being honest with yourself about before you pay extra for it.
Contact centre
This is where the six split hardest. 8x8 and AWS both do it properly, with AI routing and workforce management included. Avaya covers standard needs itself and leans on NICE CXone for anything complex. Gamma's contact centre is an add-on that is still catching up. Teams has none of this natively and 3CX only stretches to basic queues and wallboards.
Security and compliance
All six meet the basics, TLS and SRTP encryption, GDPR compliance. Beyond that it depends what you need to prove: AWS and Teams both carry FedRAMP certification if you deal with government contracts, while Gamma's UK hosting and Ofcom regulation matters more if data residency is the concern.
What it actually costs
This is the category that changes fastest and the one worth checking most often. 3CX prices by simultaneous call count, which can work out cheaper or more expensive than per-user pricing depending entirely on how your team is shaped. AWS charges purely on usage with no seats at all. 8x8's new small business pricing removes the seat count and annual term altogether, for now, under 100 users. Teams calling is billed separately from your Microsoft 365 licence. None of these map onto each other cleanly, which is exactly why totting up the actual number beats assuming your current deal is competitive.
Which one fits which business
Global or multi-site teams that want calling and customer service under one roof tend to land on 8x8. Cost-conscious small businesses happy to manage their own system lean towards 3CX. UK-only businesses already committed to Teams usually keep Teams as the interface and let Gamma handle the lines behind it. Existing Avaya customers moving to the cloud stay with Avaya Cloud Office rather than starting again elsewhere. Organisations fully standardised on Microsoft 365 with no serious contact centre need often just add Teams Phone. Enterprises building a custom, high-volume contact centre on their own AWS infrastructure are the ones who reach for Amazon Connect, and pretty much nobody else needs to.
Frequently asked
Is 8x8 cheaper than Microsoft Teams for business calling?
Usually yes for calling specifically, because 8x8 prices calling into its per-user plans while Microsoft now sells Teams Phone calling as a separate add-on rather than bundling it with a Microsoft 365 licence. Which is actually cheaper depends on how many of your Microsoft 365 seats need a phone number attached, so it is worth totting up both bills properly rather than assuming.
Can 3CX replace a full contact centre system?
No, not for anything beyond basic queues and wallboards. 3CX handles PBX calling, live chat and WhatsApp well, but it has no workforce management and no AI-driven routing. If you run a proper contact centre, 8x8 or AWS Amazon Connect are built for that job and 3CX is not.
Does Gamma work with Microsoft Teams calling?
Yes. Gamma is one of the larger UK providers of Teams Direct Routing and Operator Connect, so you can keep Teams as the interface your staff use while Gamma supplies the actual phone lines and PSTN connectivity behind it.
What is the difference between UCaaS and CCaaS?
UCaaS (Unified Communications as a Service) covers everyday business communication: calling, meetings and messaging for your whole team. CCaaS (Contact Centre as a Service) is built specifically for handling high volumes of customer contact, with queuing, routing and reporting. Some platforms, like 8x8, sell both together as one product; others, like AWS Amazon Connect, only do the CCaaS half.
Is AWS Amazon Connect suitable as a small business phone system?
No. Amazon Connect is not a PBX or a UC system, it has no office voicemail, no desk phone app and no meetings product. It is built for running a contact centre on a pay-per-use basis, and it makes most sense once you already have a phone system in place and need serious call centre capability on top of it.
Which provider has dropped seat counts and annual contracts for small teams?
8x8 has, for UK businesses under 100 users, with a pay-as-you-go model that removes the fixed seat count and the twelve-month term that most phone contracts still use. It is a genuinely different structure to how the rest of the market prices business calling, which is exactly why it is worth checking against what you are currently signed up to.
How do I know if we are overpaying for licences we don't use?
Start by counting active users against seats you are being billed for, since leavers are the most common source of waste on a phone contract. Research from Flexera puts wasted UK software spend at close to one pound in five, and phone contracts are rarely audited the way software licences now are. Sending your current bill to a reseller for a free markup, ours included, is the fastest way to get a straight answer.
If reading all of that has told you your current contract might not survive the comparison, that is worth five minutes of someone's time this week.
Talk to West Pier