VoIP Bandwidth Requirements UK: How Much Bandwidth Do You Need? Quick Answer
A standard VoIP voice call usually needs only around 80–100 Kbps of bandwidth in each direction. This means VoIP itself does not require an especially fast broadband connection – really, what matters more is:
how many calls happen at the same time
available upload and download capacity
latency
jitter
packet loss
Wi-Fi and router quality
other internet traffic sharing the connection
For example, 10 simultaneous standard VoIP calls may need roughly 1 Mbps of voice capacity , while 50 simultaneous calls may need around 5 Mbps, before allowing capacity for cloud software, video meetings, file transfers and normal internet use.
You therefore do not need 500 Mbps or 1 Gbps simply because you have 10 or 20 employees.
See our acceptable jitter and latency guide and VoIP call quality guide if your concern is call reliability rather than raw bandwidth.
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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: October 2026
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Key Takeaways
Standard VoIP voice calls typically use around 80–100 Kbps per concurrent call.
Bandwidth should be calculated from simultaneous calls, not total employee count.
Ten employees do not necessarily mean ten calls at once.
Latency, jitter and packet loss often affect call quality more than raw broadband speed.
Upload capacity matters because VoIP sends and receives voice data simultaneously.
Teams video and screen sharing use much more bandwidth than voice-only calls.
Good FTTP or business broadband can support many small and medium VoIP deployments.
Leased lines become more relevant where voice is business-critical, call volumes are high or stronger service guarantees are needed.
How Much Bandwidth Does One VoIP Call Use? The exact amount depends on the codec, packet size, encryption and network overhead.
As a practical planning guide:
VoIP call type Approximate bandwidth per call
Compressed voice
Around 30-50 Kbps
Standard G.711 voice Around 80-100 Kbps
High-quality/wideband voice
Around 100-150 Kbps depending on platform
Teams Phone audio
Roughly 58-76 Kbps per endpoint under Microsoft’s current guidance
How Do You Calculate VoIP Bandwidth? Start with the number of simultaneous calls , not your total number of staff- a simple planning formula is:
Concurrent calls × estimated bandwidth per call = approximate voice bandwidth requirement
If you use 100 Kbps as a conservative planning figure:
Simultaneous calls Approximate voice bandwidth
1
0.1 Mbps
5
0.5 Mbps
10
1 Mbps
20
2 Mbps
50
5 Mbps
100
10 Mbps
This is voice traffic only – you still need enough capacity for everything else using the connection.
Why Concurrent Calls Matter More Than Team Size A 50-person business does not necessarily have 50 people on the phone simultaneously.
For example:
a 20-person accountancy firm may have only four or five simultaneous calls
a 20-person sales floor might regularly have 15 or more simultaneous calls
a 50-person office may have most staff using email and cloud applications rather than the phone
This is why VoIP planning should be based on peak concurrent calls .
Business Employees Likely simultaneous calls Approximate voice capacity
Small office
10
2-4
0.2-0.4 Mbps
Professional-services firm
25
5-10
0.5-1 Mbps
Sales team
20
10-15
1-1.5 Mbps
Call centre
50
30-50
3-5 Mbps
These are planning examples rather than fixed requirements.
How Much Broadband Speed Does a Business Need for VoIP? There is no universal broadband speed that every VoIP business needs. Your connection should comfortably support your peak voice demand plus normal business internet usage.
Typical setup VoIP requirement What matters most
1-5 users
Very low bandwidth requirement
Stable connection and good Wi-Fi/router
5-20 users
Usually only a few Mbps for voice
Concurrent calls and other cloud traffic
20-50 users
Still modest for voice alone
Peak call volume, uploads, video and QoS
Call-heavy team
Depends on simultaneous calls
Capacity, resilience and traffic prioritisation
Large multi-site/contact centre
Higher aggregate requirement
Network design, resilience and service levels
Your business does not automatically need gigabit broadband because it has dozens of VoIP users – the rest of the organisation’s internet usage often consumes far more bandwidth than the voice traffic itself.
How Much Upload Speed Does VoIP Need? VoIP is two-way, so you need enough capacity in both directions.
For a standard call using around 100 Kbps:
5 simultaneous calls require roughly 0.5 Mbps upload
10 calls require roughly 1 Mbps
20 calls require roughly 2 Mbps
50 calls require roughly 5 Mbps
However, do not size the connection to those figures alone.
Your upload bandwidth could also be used by:
cloud backups
Teams and Zoom video
file uploads
CRM applications
cloud storage synchronisation
CCTV systems
remote desktops
The better approach is to leave plenty of headroom rather than allocating almost all available upload capacity to VoIP.
Is Upload Speed More Important Than Download Speed for VoIP? Upload speed is important, but it is not accurate to call it the single most important factor.
Good voice quality depends on a combination of:
available upload capacity
available download capacity
low latency
low jitter
minimal packet loss
stable routing
network configuration
VoIP Bandwidth vs Teams Video Voice-only calling uses very little bandwidth compared with video conferencing.
Activity Indicative bandwidth
Standard VoIP audio
Around 0.08-0.1 Mbps per call
Teams audio
Roughly 0.058-0.076 Mbps recommended/best performance per endpoint
Teams one-to-one video
Around 1.5 Mbps recommended per endpoint
Teams meeting video
Up to around 2.5 Mbps download/4 Mbps upload recommended depending on scenario
Teams screen sharing
Around 1.5-2.5 Mbps recommended depending on scenario
This distinction matters because a business may conclude that “VoIP is using all our bandwidth” when the heavier demand is actually coming from video meetings and screen sharing.
How Much Bandwidth Does Microsoft Teams Phone Need? Microsoft Teams Phone uses relatively little bandwidth for voice-only calling.
Microsoft’s current guidance lists approximately:
10 Kbps up/down minimum for audio58 Kbps up/down recommended 76 Kbps up/down for best performance
Teams Rooms and video meetings require significantly more because video and screen sharing add separate media streams.
See our Microsoft Teams Phone guide if you are comparing Teams as your main business phone system.
Does Codec Choice Affect VoIP Bandwidth? Yes.
A codec compresses and encodes the audio used by a VoIP call and fifferent codecs balance audio quality and bandwidth differently.
Codec Typical voice bandwidth profile Use
G.711
Around 80-90 Kbps once IP overhead is included
High-quality standard business voice
G.729
Around 20–30 Kbps depending on network overhead
Lower-bandwidth environments
Opus
Adaptive
Modern software-based voice and collaboration systems
Do not calculate bandwidth using the codec’s raw audio bitrate alone because RTP, IP and network headers add overhead.
Why Fast Broadband Can Still Give You Bad VoIP Calls A 500 Mbps or 1 Gbps broadband service can still produce poor VoIP if the connection is unstable and common causes include:
high latency
jitter
packet loss
congested Wi-Fi
router problems
poor traffic prioritisation
heavy uploads
ISP or routing issues
This is why broadband speed alone is not a good measure of VoIP readiness.
See our acceptable jitter and latency guide for target levels and our VoIP call quality guide for troubleshooting.
What Latency, Jitter and Packet Loss Are Good for VoIP?
Metric Useful target
Latency
Below 150ms one way
Jitter
Below 30ms
Packet loss
Below 1%, ideally close to zero
How Does QoS Help VoIP? Quality of Service can prioritise voice packets when the network becomes busy which is important because real-time voice is more sensitive to delay than most ordinary internet traffic.
For example:
a file download can take a few seconds longer
a voice packet arriving late can immediately affect a live call
Do You Need a Separate Internet Connection for VoIP? No, not necessarily! Most small and medium-sized businesses can run VoIP alongside normal internet traffic on the same connection if:
there is enough capacity
the connection is stable
network equipment is appropriate
traffic is managed correctly
Can You Run VoIP on FTTC? Yes, potentially.
FTTC can support VoIP if the actual connection provides enough stable upstream and downstream capacity for your concurrent calls and other business use, but the limitation is that some FTTC connections have relatively modest upload speeds compared with FTTP or leased lines.
Do not assume FTTC is unsuitable purely because of the connection technology – instead, test the actual service.
Is FTTP Good for VoIP? FTTP is well suited to many business VoIP deployments because it can provide substantial capacity and generally stronger upload performance than older copper-based connections.
However, broadband performance still needs to be considered alongside:
service level
contention
router quality
network design
backup connectivity
Do You Need a Leased Line for VoIP? No. A leased line is not required simply because a business uses VoIP.
It becomes more relevant where:
you have high concurrent call volumes
your phone service is business-critical
you operate a contact centre
you need symmetrical bandwidth
you need stronger service guarantees
you require reliable failover arrangements
large volumes of voice, video and cloud traffic share the connection
Leased lines provide dedicated symmetric connectivity, but they should be justified by the wider business requirement rather than the bandwidth of the VoIP calls alone.
See our business leased line comparison or leased line cost guide .
How Many VoIP Calls Can a 10 Mbps Connection Handle? At roughly 100 Kbps per call, 10 Mbps could theoretically carry around 100 simultaneous voice calls if nothing else used the connection.
In reality, you should never plan to saturate the connection this way.
You need headroom for:
normal business internet traffic
network overhead
traffic bursts
video
cloud applications
unexpected peaks
The theoretical maximum is therefore not a useful deployment target.
How Many VoIP Calls Can a 100 Mbps Connection Handle? Voice bandwidth is unlikely to be the limiting factor on a healthy 100 Mbps connection for most SMEs.
At 100 Kbps per call, 100 Mbps represents a theoretical 1,000 calls, but real networks should never be designed by dividing the entire internet connection by the codec requirement.
Instead, identify your expected peak concurrent calls and make sure they represent only a modest part of your available capacity.
What Happens When VoIP Does Not Have Enough Bandwidth? When a network becomes congested, you could experience:
robotic speech
missing words
delayed audio
one-way audio
call dropouts
poor call recording quality
However, these symptoms can also result from jitter, packet loss, Wi-Fi or provider issues, so don’t assume insufficient bandwidth is automatically the cause.
Remote Workers and VoIP Bandwidth Remote employees usually need very little bandwidth for voice alone – the challenge is that their connection could also be supporting:
Teams video
other household users
streaming
cloud backups
VPN traffic
school or family devices
For call-heavy remote users, test their actual connection under normal working conditions.
See our VoIP for remote teams guide for more detail.
VoIP Bandwidth Checklist Before deploying or expanding a VoIP system, check:
How many employees need VoIP?
How many will be on calls simultaneously?
Which codec or service will be used?
How much upload and download capacity is available?
How much bandwidth do other cloud applications use?
Do employees make video calls as well as voice calls?
What are the latency, jitter and packet-loss results?
Are users connecting by Ethernet or Wi-Fi?
Does your network support QoS?
Do you need backup connectivity?
If your connection passes these checks but call quality remains poor, the issue could sit with your network configuration, hardware or VoIP service.
Our Verdict: How Much Bandwidth Does VoIP Need? VoIP itself needs surprisingly little bandwidth.
A good planning figure for standard voice is around 100 Kbps per simultaneous call .
That means:
5 calls ≈ 0.5 Mbps
10 calls ≈ 1 Mbps
20 calls ≈ 2 Mbps
50 calls ≈ 5 Mbps
The bigger concern for most businesses is whether the connection stays stable while employees are also using video, cloud software, file transfers and other internet services.
Focus on:
concurrent calls
available capacity
latency
jitter
packet loss
QoS
network resilience
If your current connection is suitable but you are still deciding which phone system to use, compare options through our business VoIP phone systems pillar .
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Frequently Asked Questions How much bandwidth does one VoIP call use?
A standard business VoIP call commonly uses around 80–100 Kbps once network overhead is included, although the exact requirement depends on codec and configuration.
How much bandwidth do 10 VoIP calls need?
Using 100 Kbps per call as a simple planning figure, 10 simultaneous calls require roughly 1 Mbps of voice bandwidth in each direction.
How much bandwidth do 20 VoIP calls need?
Twenty simultaneous calls at roughly 100 Kbps each require around 2 Mbps of voice bandwidth, before allowing capacity for other internet traffic.
Does VoIP need fast broadband?
No. Voice itself uses very little bandwidth. Connection stability, latency, jitter, packet loss and available headroom are generally more important than headline download speed.
Is 100 Mbps enough for VoIP?
For most SMEs, 100 Mbps is more than enough for voice traffic alone. Whether the connection is sufficient overall depends on other business internet usage and the number of simultaneous calls.
Can VoIP work on a 10 Mbps connection?
Yes, potentially. A small number of VoIP calls can use much less than 10 Mbps. The connection still needs sufficient upload capacity and stable latency, jitter and packet loss.
How much upload speed does VoIP need?
Allow roughly the same capacity upstream as downstream for voice. Ten simultaneous standard calls may require around 1 Mbps of upload capacity before allowing headroom for other services.
Does Teams Phone use more bandwidth than standard VoIP?
Teams voice-only bandwidth is still relatively low. Video meetings and screen sharing use substantially more bandwidth than Teams audio.
Why is my VoIP bad even though I have fast broadband?
High jitter, latency, packet loss, congested Wi-Fi, router issues or provider routing can affect calls even when your speed test shows plenty of bandwidth.
Do I need a leased line for VoIP?
No. Many businesses can run VoIP over good FTTP or business broadband. Leased lines are more relevant where calls are business-critical, concurrent call volumes are high or stronger service guarantees are needed.
How do I calculate VoIP bandwidth?
Multiply the estimated bandwidth per call by the number of calls expected at the same time, then leave significant spare capacity for normal business internet usage.
What matters more for VoIP: speed or latency?
Both capacity and stability matter, but once you have enough bandwidth for your calls, latency, jitter and packet loss often have a greater effect on perceived call quality than additional download speed.
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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.
