Southampton • Business Phone Systems & VoIP

Business Phone Systems Southampton
Hosted VoIP, Cloud PBX & SIP for Southampton & Hampshire

T2K Voice & Data supplies business phone systems in Southampton, from port and maritime businesses around the docks to professional firms in the city centre, healthcare and research teams near the universities, and businesses across Eastleigh, Totton and the Waterside. We're a UK-based telecoms provider with 35+ years' experience, serving customers across the country. We set up Gamma Horizon, 3CX, Mitel and three other VoIP platforms, and your 023 numbers come with you.

Keep Your 023 Numbers
Remote Setup, Site Visits When Needed
35+ Years UK Experience
🛳️
Southampton
Hampshire
259,000
Population (2024)
6
Platforms Supported
35+
Years in Telecoms
Local Dialling Code
023
Southampton · T2K Voice & Data

Southampton Business Telephone Systems, Done Properly

T2K Voice & Data is an independent, UK-based telecoms provider serving customers across the country, Southampton and Hampshire included. Hosted systems are configured and tested before go-live, handsets arrive pre-provisioned and 023 numbers port across through the network. Where a site needs an engineer, such as dockside DECT coverage or an on-premise PBX swap, we plan the visit with you.

We supply the full telecoms stack for Southampton businesses: cloud phone systems, on-premise PBX, SIP trunks, Microsoft Teams calling, business broadband, leased lines and mobiles, all on one contract.

35+
Years in UK Telecoms
4.9/5
Rated on Google
6
Platforms — Vendor Agnostic
Talk to a Specialist About Your Southampton Business →
Southampton Business

Southampton's Business Landscape & What It Needs from a Phone System

Southampton is a major port city and the UK's busiest cruise port, with a large marine and maritime sector around the docks and along Southampton Water. Healthcare and medical research, two universities, retail and professional services in the city centre round out the economy.

Shipping, freight and marine businesses need calls that follow staff around terminals and yards, plus ring groups and out-of-hours routing for round-the-clock operations. Healthcare and research organisations need reliable queues, recording and clear routing for patients and partners.

Retailers, hotels and hospitality venues in the city centre need call handling that copes with cruise-day and seasonal peaks, while accountants and solicitors want call recording and consistent caller ID. Moving off analogue or ISDN lines follows the same steps for all of them.

Local Numbers

Keep Your Southampton 023 Number — VoIP or Mobile

Every Southampton 023 number can move to a VoIP phone system or divert straight to a mobile. The 023 code also covers Portsmouth, so businesses across South Hampshire share a recognisable local number.

023 XXXX XXXX
Southampton Geographic Number

023 Numbers Work with VoIP or Mobile Divert

Keep the number your customers know. We port 023 numbers onto whichever platform you choose, or simply divert them to a mobile, and your old line stays live until the switch.

  • Keep your existing Southampton 023 number
  • Port to any VoIP platform (Horizon, 3CX, Mitel, etc.) or divert to mobile
  • No gap in service during the switch
📲
Buy or Port a Southampton 023 Number
Route it to VoIP or a mobile — check availability and request a port online
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Browse & buy UK telephone numbers
Geographic, 0800 freephone and 03 numbers — same-day activation
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UK area code finder
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Systems

Business Phone Systems We Supply in Southampton

We work with six business telephone system platforms, from fully hosted VoIP to on-premise PBX, and recommend what fits your operation for Southampton firms rather than pushing one vendor.

HZN
Gamma Horizon
Best for: Southampton SMEs (5–500 users)

Gamma's flagship hosted platform, running on Gamma's own UK network. It suits Southampton offices that want dependable calling, a mobile app and Teams integration without any kit in the comms cupboard.

  • Hosted cloud — zero on-site hardware
  • Keep your Southampton 023 numbers
  • Microsoft Teams integration available
3CX
3CX
Best for: CRM Integration & Control

A software IP PBX with deep CRM integration and strong multi-site features. Our Pennyfarthing Homes project below shows it in action. T2K Voice & Data is a 3CX Titanium Partner.

  • Native CRM integration (50+ platforms)
  • Cloud, on-prem, or hybrid deployment
  • Video conferencing included
MITEL
Mitel MiVoice Business
Best for: Maritime & Large Organisations

An enterprise unified communications platform for larger Hampshire organisations, including port-side operators and multi-site groups needing on-premise control. T2K has decades of Mitel experience.

  • Multi-site unified communications
  • Enterprise contact centre capabilities
  • Resilient architecture
WBX
Gamma Webex
Best for: Hybrid & Collaboration-First Teams

Cisco Webex calling, meetings and messaging over Gamma's UK carrier network. Suits research and professional teams working across sites.

  • Video-first unified communications
  • Cisco Webex platform quality
  • Gamma UK carrier delivery
PL+
Phoneline+
Best for: Simplest PSTN Replacement

If you run a Southampton shop, practice or small office with one or two lines, Phoneline+ replaces them with a digital service while keeping your 023 number and the phone on the desk.

  • No new hardware — use existing phones
  • Lowest-cost PSTN replacement
  • Keep your Southampton 023 number
FLOW
Voiceflex Flow
Best for: UCaaS, CRM & Teams integration

A flexible UCaaS platform with calls, messaging and meetings in one app. Well suited to Southampton firms on Microsoft 365.

  • Native Microsoft Teams integration
  • Advanced routing with ACD and IVR
  • Integrates seamlessly with major CRMs
Still weighing up the options for your Southampton business? Book a free consultation and we'll compare two or three platforms against how your team actually uses the phone, with no obligation to buy.
Free tool
Not sure which phone system is right for you?
Answer 7 quick questions about your business and our phone system finder will match you against all six systems T2K Voice & Data provides — returning a ranked recommendation in under two minutes.
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Takes under 2 minutes · Free to use
Case Study

Unified 3CX Migration: Pennyfarthing Homes

70
Users Migrated
100%
Numbers Ported
1
Unified Platform
Hampshire 3CX Deployment
Pennyfarthing Homes — Multi-Site Housebuilder Future-Proofs with 3CX
Pennyfarthing Homes, a housebuilder working across Hampshire and Dorset, was relying on an end-of-life on-premise PBX and ISDN2e lines. T2K Voice & Data moved its 70-strong team onto a single 3CX cloud platform, ported every existing number and added remote working, call recording and multi-site calling, with no loss of service during the switch.
Read the full case study →
FAQ

Business Phone Systems & VoIP in Southampton — Frequently Asked Questions

Questions we regularly hear from Southampton businesses comparing VoIP providers and phone systems.

Can I keep my Southampton 023 phone numbers when switching to VoIP?
Yes. Any 023 number can be ported to a VoIP phone system with no gap in service. T2K Voice & Data manages the porting from start to finish.
Do you provide on-site support for Southampton businesses?
Most phone systems are installed and supported remotely, but Hampshire is close to home for us, so on-site visits for DECT surveys, PBX swaps or multi-site installs are straightforward to arrange. We'll confirm what's needed before you sign.
How much does a business phone system cost in Southampton?
For most Southampton SMEs with 5–50 users, hosted platforms such as Gamma Horizon or 3CX cost around £10–£20 per user per month. Larger and multi-site organisations usually suit Mitel or 3CX on custom pricing. Every quote is itemised.
How long does a VoIP migration take for a Southampton business?
Most single-site Southampton businesses go live within a couple of weeks of sign-off, with the cutover out of hours. Multi-site rollouts across Hampshire typically take 4–8 weeks.
Can our phone system run 24/7 for port and shipping operations?
Yes. Time-of-day routing, out-of-hours rotas and mobile apps keep calls flowing round the clock, and calls can follow duty staff to their mobiles on the same 023 number.
Do Southampton businesses need to replace analogue and ISDN phone lines?
Yes. Openreach is retiring the UK's traditional PSTN and ISDN network, including every exchange in Southampton and South Hampshire, so businesses still on analogue lines, ISDN2 or ISDN30 need to move to VoIP, SIP trunks or a digital line replacement. Check where your lines stand with our PSTN switch-off checker.
Coverage Area

Southampton Postcodes We Serve

We supply business phone systems and VoIP across every SO postcode district, covering Southampton, Eastleigh, Winchester, Romsey and the New Forest. Expand a group below to find your area.

Southampton City & Inner Suburbs SO14 – SO19 ›
SO14City Centre, Ocean Village & St Mary's
SO15Shirley, Freemantle & the Western Docks
SO16Bassett, Lordshill & Nursling
SO17Highfield & Portswood
SO18Bitterne & Harefield
SO19Sholing, Woolston & Thornhill
Winchester & Alresford SO21 – SO24 ›
SO21Colden Common & Twyford
SO22Winchester (west) & Hursley
SO23Winchester city centre
SO24New Alresford
Eastleigh, Romsey & Southampton East SO30 – SO32, SO50 – SO53 ›
SO30Hedge End, Botley & West End
SO31Hamble, Warsash & Locks Heath
SO32Bishop's Waltham
SO50Eastleigh, Bishopstoke & Fair Oak
SO51Romsey
SO52North Baddesley
SO53Chandler's Ford
New Forest & Waterside SO40 – SO45 ›
SO40Totton & Marchwood
SO41Lymington & Milford-on-Sea
SO42Brockenhurst & Beaulieu
SO43Lyndhurst
SO45Hythe & Fawley
Test Valley SO20 ›
SO20Stockbridge & Middle Wallop

Not seeing your postcode? Get in touch — we serve customers right across the UK.

Nearby Areas

Southampton Business Districts & Nearby Towns

We have dedicated pages for three Southampton-area business districts, and supply phone systems right across Hampshire and Dorset. Distances are straight-line from Southampton city centre.

Ready to Upgrade Your Southampton Business Phone System?

Whether you're replacing ISDN, an old PBX or a single analogue line, T2K Voice & Data can move your Southampton business to VoIP while keeping your 023 numbers and your phones working throughout.

📞 Call us on 0808 202 3200 — Mon–Fri, 9am–5pm