Multi-Site VoIP Phone System for UK Businesses

What is a multi-site VoIP phone system?

A multi-site VoIP phone system replaces separate phone lines at each location with one cloud platform that all your sites log into. Staff in Sheffield, Manchester and home offices appear in the same directory, dial each other by extension, and share queues — managed centrally rather than site by site.

This is the natural successor to the analogue phone network, which Ofcom confirms is being retired as the UK migrates landline services to digital, internet-based technology (Ofcom). If you run more than one location, a unified system removes the cost and admin of maintaining a separate phone setup per site. It sits inside our wider business VoIP offering, so call plans, handsets and softphones are configured once and applied everywhere.

What's included in a multi-site VoIP system?

A multi-site deployment gives every location the same features and the same control. Instead of each office running its own island of telephony, you get one directory, one routing engine and one portal. The result is lower call costs, consistent customer handling and far less day-to-day management overhead.

• Single extension directory — every employee at every site has an extension reachable from any other site. Calling a Manchester colleague from Sheffield is just dialling the extension: no external call charges, no looking up site numbers.
• Intelligent call routing — route inbound calls by DDI number, by time of day, or by overflow rules so a main number can ring head office in hours and divert to a second site after.
• Shared hunt groups and call queues — sales, support and accounts teams that span sites answer from one queue, so a customer reaches whoever is free regardless of location.
• Centralised management — users, extensions, queues, auto-attendant menus and call recording are all administered from one web portal, not by chasing different IT contacts per office.
• Free inter-site calls — calls between your locations travel as data over your existing connections, removing inter-site PSTN charges entirely.

How does AMVIA connect your sites with VoIP?

We deploy multi-site VoIP in four controlled stages so each location goes live without disrupting the ones already running. Survey first, design one unified plan, roll out site by site with number porting tested at each step, then hand over a single managed platform.

01. Multi-site survey — we assess network readiness, bandwidth and call routing needs at every location. 02. System design — a unified call plan with site-to-site dialling, centralised reception and local breakout where needed. 03. Phased rollout — handsets and softphones deploy site by site, with number porting and routing tested at each stage. 04. Unified management — all sites run from one platform with centralised reporting, call recording and ongoing UK support.

Where a site handles heavy concurrent call volumes, we pair the deployment with the right connectivity — typically a leased line for HQ and quality business broadband with QoS for smaller offices. See our multi-site connectivity approach for how the network underneath is built.

Multi-site VoIP vs traditional multi-site phone lines

The difference between one cloud system and a phone setup per site shows up in cost, management and resilience. The table below compares the two for a typical UK business running three or more locations.

How does multi-site VoIP handle security?

Because calls and management run over your internet connection, the phone system becomes part of your attack surface — and should be secured like any other business application. We harden the platform with enforced authentication, fraud monitoring and encrypted call signalling, and we treat telephony as a security service, not a telecoms add-on.

The NCSC sets out why voice and collaboration tooling needs the same controls as email and endpoints (NCSC). For Microsoft-centric organisations, calls can run through Teams using Microsoft Teams Direct Routing, which keeps voice inside the same identity and Conditional Access controls as the rest of Microsoft 365 (Microsoft Learn). If telephony security is your priority, our VoIP security guidance covers the full control set.

Why choose AMVIA for multi-site VoIP?

AMVIA runs telephony for UK businesses as a security partner, not a reseller — so your phone system is designed, deployed and monitored by Microsoft-certified engineers under one accountable contract.

• Sheffield-based, UK-focused — our engineering and support team operates from Sheffield and understands UK compliance and network realities.
• Accredited and certified — AMVIA holds Cyber Essentials Plus certification and Microsoft Solutions Partner status.
• 1,200+ UK businesses — we manage IT and security for over 1,200 UK businesses across legal, finance, healthcare and professional services.
• Fast, responsive support — critical issues carry a <1hr critical issue response time, with phone, email and portal access and named account managers.

If your sites also need a single-site system or trunk-only setup, our hosted phone system and SIP trunks pages cover those options.