What is Contact Centre as a Service (CCaaS)?

By Scott Aldridge, Director, PrimeTel · September 2026

Key points

A SIP trunk connects your existing phone system to the public telephone network over an internet connection.
A SIP channel represents the capacity for one concurrent incoming or outgoing call.
The number of SIP trunk channels you need is usually determined by peak simultaneous call demand, not simply your number of employees.
One SIP trunk can support multiple channels, so businesses don’t generally need a separate trunk for every user or telephone number.
Allowing some additional capacity for busy periods and future growth can prevent avoidable call congestion.
The right setup should consider resilience, connectivity and future communications requirements as well as today’s call volumes.

Contact Centre as a Service (CCaaS) is customer service software that runs in the cloud instead of on equipment in your building.

It brings phone calls, emails, live chat, WhatsApp and social messages into one system, so your team handles every customer conversation from a single screen. You pay a monthly fee for each agent rather than buying and maintaining hardware.

What does a CCaaS platform cover?

Two things: the channels your customers use to reach you, and the tools your team needs to handle them well.

The channels

The “channels” are voice calls, email, live chat on your website, SMS, WhatsApp, social media messages, and on some platforms, video.

All in a single system, not spread out over multiple.

This means your customer service agents don’t need to switch between four different programmes as customers get in touch via different avenues, and a customer who starts a conversation on chat and then rings up doesn’t have to explain themselves twice.

The tools

A typical platform includes call routing, an automated menu, call recording, live and historical reporting, quality checking, staff scheduling, and connections into your customer database. Most now include some form of AI, whether that’s summarising conversations, suggesting answers to agents while they’re talking, or handling straightforward questions without a person involved at all.

Not every platform includes all this as standard. Some sell the scheduling and quality tools as separate modules, so it’s always worth checking what’s on the plan you’re being quoted.

How does CCaaS work?

The software sits in your supplier’s data centres rather than on servers in your office. Your agents log in through a web browser or an app, from the office, from home, or from anywhere with a decent internet connection.

There’s no phone system to install, no contact centre hardware to buy, and no engineer visit when you want to change how calls are routed. Your supplier handles updates and maintenance in the background, so new features are implemented automatically with a simple update. Adding or removing agents is done through an admin page, usually in a few minutes.

Learn more about CCaaS

What is the difference between a hosted contact centre and a cloud contact centre?

Functionally, they’re practically indistinguishable from one another, with the main difference being that a cloud contact centre is built specifically to be used remotely, whereas a hosted contact centre often means a traditional system has been migrated to a supplier’s data centre.

Hosted contact centres are perfectly adequate, but they’re often updated more slowly, have fewer channels, and come with tricky licence models to manage.

CCaaS is built for the cloud. It’s updated continuously, designed around multiple channels rather than extras being added later, and is built to allow capacity to move up and down.

Realistically speaking, if you’re looking for a complete upgrade, we’d usually recommend a cloud contact centre. If you already have a system and want to make it a bit more practical, a hosted contact centre could work better for you (but CCaaS will still be a big upgrade).

What is the difference between CCaaS and a hosted phone system?

A hosted phone system is for your whole business. Everyone gets an extension, calls get answered and transferred, there’s voicemail and some basic reporting. It’s built around a business making and taking calls in the ordinary course of work.

A CCaaS platform is for the team whose entire job is talking to customers. It’s built around volume and measurement: queuing callers fairly, routing them by who’s best placed to help, recording and scoring conversations, tracking how long people wait, and forecasting how many staff you’ll need next week.

Plenty of businesses need both. A law firm might run a hosted phone system for its solicitors and a contact centre platform for its client services desk.

What is the difference between CCaaS and UCaaS?

UCaaS stands for Unified Communications as a Service. It’s the software your staff use to talk to each other: internal calls, video meetings, instant messaging and file sharing. Microsoft Teams and Zoom are the two most people will recognise.

CCaaS is the software your customers reach you through.

In short: UCaaS is how your team talks internally, CCaaS is how your customers talk to you.

Several suppliers now sell both, sometimes on one platform, which is useful when an agent needs to grab a colleague mid-call to answer a question. If you already run Teams or Zoom internally, you’ll want a CCaaS platform that integrates with it properly, because this will save an awful lot of transferring calls around!

Need advice? Reach out to our CCaaS experts

Who uses CCaaS?

CCaaS is most valuable to businesses that handle a lot of customer contact, or handle it across more than one channel. This covers:

Retailers
Travel companies
Utilities providers
Insurers
Banks
Pretty much anyone running a customer service desk.

It also covers plenty of businesses that don’t think of themselves as having a contact centre at all.

Hotel groups taking reservations centrally.
Recruitment firms where consultants are on the phone all day.
Law firms with a client enquiries team.
A council handling residents’ questions.
A school trust fielding parent calls during admissions.

It’s also common among businesses replacing something older. If your current setup is a phone system with a queue bolted onto it, and you keep your emails/chats separately, CCaaS can help integrate everything into one.

Common CCaaS terms explained

ACD (automatic call distribution): The engine that decides which agent gets which contact, based on rules you set.

IVR (interactive voice response): The automated menu that answers and asks the caller to choose an option.

Omnichannel: Handling every channel in one place, with the customer’s history carrying across all of them.

Skills-based routing: Sending a customer to the agent best equipped to help, rather than whoever is next.

Workforce management (WFM): Forecasting how busy you’ll be and building staff rotas to match.

Quality monitoring: Scoring conversations to check standards are being met, increasingly done automatically rather than by sampling.

Agent assist: AI prompts and suggested answers appearing on screen while the agent is still in the conversation.

Abandonment rate: The percentage of customers who give up before anyone answers.

First contact resolution: The percentage of enquiries sorted out in one interaction, without a callback or a second attempt.

Wrap-up time: The time an agent spends finishing notes and admin after a conversation ends.

Considering CCaaS? If you’re not sure where to start, give us a shout

We’re completely impartial technology consultants. It’s our job to learn all about your business (and customers) and find you the best possible CCaaS platform, suited to your unique needs and workflows.

You don’t pay us, the suppliers do, and we charge a flat rate regardless of who we serve, which means there are no biases and you have nothing to lose by working with us.

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