How Much Bandwidth Do You Really Need for Business VoIP? (2026 UK Speed Requirements Guide) Quick Answer
Most UK businesses need at least 100Mbps broadband or a 100Mbps leased line to run VoIP reliably, but VoIP itself uses very little bandwidth: 0.1–0.5 Mbps per call depending on codec quality. What really matters is upload speed, latency (<50ms) and jitter (<20ms), so for teams with 10+ staff, cloud apps or remote workers, 500Mbps–1Gbps provides the best performance.
VoIP calls require far less speed than most people think, but they rely heavily on connection stability, and our guide explains exactly how much bandwidth UK businesses need for VoIP, how VoIP uses your network, and what internet speeds different team sizes should choose.
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Authored by: Ally Cox (Business Technology & B2B Services Specialist 10+ Years’ Experience)
Reviewed by: James Ward (Telecoms Specialist, 12+ Years Experience)
Last Updated:January 2026
Contents:
What Is VoIP Bandwidth and Why Does It Matter?
How Much Bandwidth Does a VoIP Call Use?
How Much Internet Speed Do You Need for Business VoIP?
What Upload Speed Is Needed for VoIP?
What Happens If Your Bandwidth Is Too Low?
How Many VoIP Calls Can Your Internet Handle?
Is a Leased Line Better for VoIP?
What Is VoIP Bandwidth and Why Does It Matter? VoIP uses your internet connection to send voice data packets. While each call needs very little download power, the upload requirement (and connection stability) is crucial.
Here’s what affects VoIP performance:
Upload speed
Latency (ping)
Jitter
Packet loss
How many concurrent calls are made
Even if you have fast broadband (like FTTP 900Mbps), high jitter or weak uploads can cause call drops.
How Much Bandwidth Does a VoIP Call Use? Different VoIP codecs use different amounts of bandwidth.
VoIP Bandwidth by Codec (per call)
Codec Quality Bandwidth required Notes
G.711
HD voice
0.10 Mbps
Highest quality, most common
G.722
Wideband
0.08 Mbps
Good for Teams/Zoom voice
G.729
Compressed
0.03 Mbps
Low bandwidth environments
Opus
Dynamic HD
0.03–0.5 Mbps
Best performance, flexible
Even HD VoIP uses less bandwidth than streaming a YouTube video.
How Much Internet Speed Do You Need for Business VoIP? Recommended Minimum Speeds (UK SMEs)
Team Size Concurrent Calls Minimum Connection Ideal Connection
1–5 users
1–5 calls
30–50Mbps FTTP
100Mbps
5–10 users
5–10 calls
100Mbps
100–300Mbps
10–20 users
10–20 calls
100–300Mbps
500Mbps
20–50 users
20–50 calls
300–500Mbps
1Gbps
50+ users
50+ calls
500Mbps–1Gbps
1–10Gbps leased line
Even where speed is adequate, you must ensure good upload speed. FTTP usually provides 50–100Mbps uploads, while leased lines offer symmetrical uploads.
What Upload Speed Is Needed for VoIP? Upload speed is the single most important factor – remember that!
Recommended upload speeds
Small teams: 10–20Mbps
Medium teams (10–20 users): 30–50Mbps
Large teams (20–50 users): 50–100Mbps
Enterprise: 100Mbps+
FTTC broadband often fails here because it only delivers 5–20Mbps upload.
What Happens If Your Bandwidth Is Too Low? VoIP issues caused by poor stability include:
Call dropouts
Robotic/distorted audio
Lag on customer calls
One-way audio
Failed call recordings
Jitter >20ms causing echo
These issues occur more from instability, not speed.
How Many VoIP Calls Can Your Internet Handle? Use this formula :
Available upload speed ÷ 0.1 Mbps = Maximum HD concurrent VoIP calls
Example
50 Mbps upload → up to 500 calls (theoretically)
In practice, you must reserve bandwidth for:
CRM systems
Cloud apps
Video meetings
Guest WiFi
We recommend using 20–30% of your upload for VoIP only.
Is a Leased Line Better for VoIP? Yes, especially for teams using:
VoIP call centres
Salesforce or HubSpot CRMs
Microsoft Teams phone systems
Large customer service queues
Remote workers
Benefits of leased lines for VoIP:
Guaranteed symmetrical speeds
99.95–99.99% uptime
Ultra-low latency (5–10ms)
No bandwidth sharing
VoIP Bandwidth Requirements vs Other Tools
Activity Minimum Required Bandwidth
VoIP call
0.1 Mbps
HD VoIP call
0.2–0.5 Mbps
Zoom HD video
2–3 Mbps
Teams video
1.5–4 Mbps
Large file upload
10–20 Mbps+
Key Takeaways
✔ VoIP uses very little bandwidth (0.1–0.5 Mbps per call).
✔ Upload speed, jitter and latency are far more important than download speed.
✔ Most UK SMEs perform best with 100–500Mbps connections.
✔ Remote teams and call centres benefit from 1Gbps leased lines.
✔ FTTC is often unsuitable due to weak upload speeds.
✔ Use 20–30% of your upload bandwidth solely for VoIP traffic.
FAQs 1. How much bandwidth do I need for VoIP in the UK?
Small teams need around 100Mbps; larger teams (20+) should aim for 500Mbps–1Gbps, especially if using cloud apps.
2. How much bandwidth does a VoIP call use?
Between 0.03–0.5 Mbps depending on codec and call quality.
3. Why does VoIP need upload speed?
VoIP sends voice data in real time, making upload speed more important than download speed.
4. Can I run VoIP on FTTC broadband?
Yes, but performance may be unreliable due to low upload speeds.
5. Is a leased line better for VoIP?
Yes, leased lines offer symmetrical speeds, low latency and no contention.
6. How many VoIP calls can 100Mbps handle?
Around 1,000 theoretical calls, but realistically far fewer once sharing the network.
7. What affects VoIP call quality?
Latency, jitter, packet loss, and upload congestion.
Here is a Handy Youtube Video About How Much Bandwidth Do You Really Need for Business VoIP?
How Much Bandwidth Do You Really Need for Business VoIP? – Other Useful Links About VoIP Hi, I’m Ally Cox , a senior copywriter and blogger at CompareYourBusinessCosts.co.uk, the UK’s trusted platform for comparing business services.over a decade of experience in the B2B sector, I specialise in simplifying complex topics like leased lines, VoIP, business energy, HR and payroll solutions, accounting software, and EPOS systems .HR, copywriting, and business operations- from clocking-in systems to card machines and office technology .informed, confident decisions when choosing products and services that improve efficiency and save money.
