Short answer: A free IP telephony service lets you make calls over the internet instead of a copper phone line. App-to-app calls are usually free, while calls to normal landlines and mobiles usually cost money. For a solo worker or a very small team it can be enough. A growing business usually needs a paid plan for a proper phone number, support, call recording and reliable 999 access.
Picture a small bakery owner in Leeds. Her landline bill keeps rising, and her provider has just written to say the old copper line is being switched off. A friend tells her, “Just use a free internet phone app.” So she wonders: can a free IP telephony service really run a business phone, or is “free” a trap?
This guide answers that question. You will learn how internet calling works, what “free” really includes, where it falls short, and the exact point where paying makes sense.
Jump to: How it works · What “free” covers · Myths vs reality · Free vs paid · Who it suits · 999 and safety · Call quality · FAQ · 7-day plan
Why Is Everyone Talking About Internet Calling Right Now?
In the UK, the old analogue phone network (the PSTN) is closing. Openreach has set 31 January 2027 as the switch-off date, and the UK government’s guidance explains that landlines are moving to internet-based technology such as VoIP, Digital Voice or all-IP telephony.
So every business phone will soon run over the internet anyway. The real question is no longer “Should I use IP telephony?” but “Do I pay for it, or can a free IP telephony service do the job?”
How Does a Free IP Telephony Service Work?
IP telephony (also called VoIP, Voice over Internet Protocol) turns your voice into small data packets and sends them over the internet, just like an email or a video stream. Here is the journey of one call:
- You speak into a phone app, a computer headset or a desk IP phone.
- A codec compresses your voice into digital data. A codec is simply the “language” that packs and unpacks sound.
- The packets travel across your broadband or mobile data to the provider’s servers.
- The other person hears you. If they use the same app, the call stays on the internet. If they have a normal phone, the provider passes the call into the phone network through a “gateway”.
That last step explains why most providers can give some calls away for free and charge for others. Internet-to-internet calls cost the provider very little. Passing a call into the traditional phone network costs them money, so they pass that cost on to you.
What Does “Free” Actually Include?
“Free” can mean very different things. Most offers fall into one of these four types:
| Type of free service | What you usually get | The catch |
|---|---|---|
| App-to-app calling | Unlimited voice and video calls between users of the same app | Usually no business phone number, and many apps say they do not support emergency calls |
| Free SIP account | A login you can use in a softphone or desk IP phone | Calls to landlines and mobiles are often paid, and you get little support |
| Free business plan | A small number of users and basic features | Strict limits on users, minutes or features |
| Free trial | Full paid features for a short time | It ends, and then you pay |
Tip: Before you sign up, read the provider’s pricing page for three words: “outbound”, “number” and “fair use”. These tell you what you will really pay for.
Which Common Beliefs About Free Internet Calling Are Wrong?
| Myth | Reality |
|---|---|
| “Free means every call is free.” | Usually only calls inside the same network or app are free. Calls to normal numbers often cost extra. |
| “Internet calls always sound worse.” | On a stable connection, VoIP can sound as clear as a landline. Poor quality usually comes from weak Wi-Fi or a busy network. |
| “I need very fast broadband.” | One call needs only around 100 kbps. Stability matters more than speed. |
| “It works in a power cut like my old phone.” | Old copper lines got power from the exchange. Your router needs mains power, so internet calling stops in a power cut unless you have a backup. |
A free service is a starting point, not a full business phone system.
How Does a Free IP Telephony Service Compare With Paid VoIP?
| Feature | Free IP telephony service | Paid business VoIP |
|---|---|---|
| Cost | £0 for basic use | Monthly fee per user or per line |
| Business phone number | Rarely included | Usually included; you can often move your existing number across |
| Calls to landlines and mobiles | Often paid per minute | Often bundled minutes |
| Call routing, voicemail, IVR menus | Basic or none | Full set |
| Call recording and reports | Rare | Common |
| 999 / 112 access | Often not supported by app-based services | Regulated UK phone services must provide it |
| Support | Help pages and forums | Phone, chat or email support |
Who Is a Free IP Telephony Service Good Enough For?
✅ Good fit: freelancers who mostly talk to clients over apps, students, remote teams that call each other internally, and side businesses testing an idea. If you are just starting out, it fits well with the ideas in our guide on how to start a side business with no money.
⚠️ Borderline: a shop or salon with 2 to 5 staff. A free service can handle internal calls, but customers will expect one public number, voicemail and calls passed between staff.
❌ Poor fit: clinics, care services, trades that take emergency call-outs, and any business where a missed or failed call loses money or puts people at risk.
Real-life example: a two-person web design studio talks to clients mostly over video calls. A free app covers 90% of its calling. The only paid item it needs is a cheap number for clients who still want to “just ring”. Compare that with a plumber taking urgent jobs from the public: he needs a reliable number, voicemail and calls that reach his mobile. A free app alone would cost him jobs.
Can You Call 999 on a Free IP Telephony Service?
This is the most important limit to understand. In the UK, Ofcom’s rules say any provider of a voice communications service must make sure customers have uninterrupted access to emergency organisations (General Condition A3.2(b)). Ofcom’s power cut guidance also notes that, without other measures, calls over broadband will not work in a power cut, because the equipment at your premises needs mains power.
Many free calling apps are not full phone services, and some say plainly in their terms that they do not support emergency calls. So:
- Always keep a working mobile phone as your emergency backup.
- If anyone at your premises depends on a landline for safety (for example, an elderly relative or a telecare alarm), tell your provider. Ofcom expects providers to offer a backup solution for such customers.
- When you do call 999 over the internet, be ready to say your address clearly, because your location may not be passed on automatically.
What Internet Connection Do You Need for Clear Calls?
Good news: internet calls need very little speed. Here are the key numbers:
- Bandwidth: a call using the common G.711 codec uses about 87 kbps in each direction. A safe planning figure is 100 kbps per call. Five calls at once need only about 0.5 Mbps up and down.
- Delay (latency): the ITU’s G.114 recommendation says a one-way delay under 150 ms is acceptable for most uses, while anything over 400 ms is not acceptable for general network planning.
- Stability: jitter (uneven packet timing) and packet loss cause robotic or broken audio. A wired connection or strong Wi-Fi helps much more than a faster package.
Quick test: run any online speed test that shows “ping” or latency. If ping stays under about 100 ms and upload speed is above 1 Mbps, a small team can usually make clear calls.
Is a Free IP Telephony Service Safe for Business Calls?
Calling over the internet brings a few risks that old landlines did not have:
- Account hijacking: if someone steals your SIP login, they can make expensive international calls on your account. Use strong, unique passwords and turn on two-factor login where offered.
- Privacy: check whether calls are encrypted and where call records are stored. If you record calls with customers, UK data protection law applies.
- Unpaid credit limits: if a free account can top up with credit, set a low limit so a hacked account cannot run up big charges.
Frequently Asked Questions
Is a free IP telephony service legal in the UK?
Yes. Using internet calling apps and VoIP services is legal. Providers that offer calls to normal UK phone numbers must follow Ofcom’s rules, including on emergency calls.
Can I keep my existing business number on a free plan?
Usually not. Moving (porting) a number is mostly a paid-plan feature. Check this before you cancel your current line.
Will a free IP telephony service work on my mobile?
Yes. Most services have apps for Android and iPhone. Calls then use your mobile data or Wi-Fi.
How much data does an internet call use?
At around 87 kbps each way, a one-hour call can use roughly 40 MB in each direction, or about 80 MB in total. Compressed codecs use much less.
When should I upgrade to a paid plan?
Upgrade when customers call you every day, when more than one person needs to answer the same number, or when you need call recording, menus or reliable 999 access.
Your 7-Day Plan to Test a Free IP Telephony Service
- Day 1: List who you call most: internal team, customers, suppliers.
- Day 2: Run a speed test and note your ping and upload speed.
- Day 3: Sign up for one free service and install it on your phone and computer.
- Day 4: Make 10 test calls to the app, to a mobile and to a landline. Note the quality and any charges.
- Day 5: Check what the service says about 999 calls, numbers and fair use limits.
- Day 6: Add up the cost of the calls a free plan would not cover. Our guide to managing cash flow in a small business can help you plan these costs.
- Day 7: Decide: stay free, mix free with a cheap number, or move to a paid plan.
Once your calls are sorted, you can also handle routine customer questions automatically. See our guide on how to choose the right AI powered chatbot platform.
A free IP telephony service is a smart way to cut costs and learn how internet calling works. Use it for what it does well, keep a mobile for emergencies, and upgrade once calls start to bring in your income.
