Hosted PBX vs On-Premises PBX: Costs, Continuity and Growth

For many companies, the phone system is still a cabinet in a corner of the office: a box bought years ago, a maintenance contract and a technician to call when something stops working. Meanwhile, the way people work has changed: multiple offices, staff working from home, customers who expect someone to pick up every time.

A hosted PBX (also called a cloud PBX or virtual PBX) moves the logic of the phone system from your premises to a provider’s data centers. Below we compare the two models on four practical points: how they work, what they cost over time, what happens when something fails and how they support growth. At the end you will also find the cases in which an on-premises PBX can still make sense.

Two architectures, one question: where does the PBX live?

Virtual PBX, IP-PBX, cloud phone system: the names vary, but the fundamental difference comes down to one thing, namely where the system that routes your calls physically sits.

The on-premises PBX

In the traditional model, the company buys and houses the hardware: the PBX itself, line cards and sometimes a dedicated server. Installation, configuration, upgrades, security patches and repairs are all down to the company, its IT team or an outside installer.

It is a self-contained system, which is why it is often seen as “more under control”. In practice, however, control depends on the time and skills you can devote to it: a box that is not updated regularly is less secure, not more.

The hosted PBX

With a hosted PBX, call routing, auto attendants and system rules run in secure, monitored data centers. The provider manages the infrastructure, updates and service availability; your team uses IP phones, the desktop app or the mobile app, always with the same business number.

With EagleMercury Elevate, each user can have up to 5 desk phones plus the desktop and mobile apps, and a call can move from one device to another without dropping. Settings are changed from a single admin portal, not by fiddling with cables and hardware.

Costs over a 3–5 year horizon

Comparing the two models on purchase price alone is misleading. It is better to look at the total cost over several years, because an on-premises PBX comes with recurring items:

• Upfront investment in hardware, licenses and installation.
• Annual maintenance contracts, which add up year after year.
• IT staff time or outside technicians for updates, changes and repairs.
• Hardware replacement after a few years, when the equipment becomes obsolete or falls out of support, and the initial investment starts all over again.
• Step-by-step growth: new lines or new offices often require additional cards or equipment.

With a hosted PBX, spending becomes a monthly fee per user, with no hardware investment. The items to compare are the fee, any desk phones (optional: the apps are enough) and connectivity. The outcome depends on your situation, but the budget becomes more predictable and the resources you free up can go to more useful work than keeping an old system alive.

Business continuity: what happens when something goes wrong

An on-premises PBX is only as reliable as the environment it sits in. A power cut, a hardware fault, a flooded room or a dropped internet line can make your company unreachable. Callers hear endless ringing, a voicemail box or silence, and a prospective customer will often try a competitor straight away.

With a hosted PBX, the call does not hit a dead end. If the office loses its connection, forwarding rules send calls to other numbers or to the mobile apps, and the team keeps answering from their smartphones. The infrastructure lives in the provider’s data centers, monitored around the clock with redundant copies, and the EagleMercury platform is backed by a 99.999% availability SLA.

To learn more about encryption, two-factor authentication and communications archiving, see the Security and archiving page.

Growth, new offices and remote work

This is where the differences are most noticeable. With an on-premises system, connecting someone who works from home or a new branch often requires VPNs, dedicated configuration and IT time: every remote employee becomes a small project.

With a hosted PBX:

• a new user is added from the admin portal, with no hardware work;
• remote staff use the apps with the business number, wherever they have a connection;
• you can activate local and toll-free numbers in Italy and other European countries, and keep your current numbers through number porting;
• multi-level auto attendants and IVR, including in several languages, route calls according to business hours and holidays;
• the phone works together with chat, SMS and video meetings, with the most widely used CRMs and with Microsoft 365 and Outlook.

All the telephony features are described on the cloud phone system page.

When an on-premises PBX can still make sense

The cloud is the natural choice for most companies, but not for all of them. An on-premises PBX can remain a reasonable option when:

• the company has recently invested in a system that is still far from the end of its life cycle;
• there are specific constraints on where data is located or on systems connected to the phones, to be assessed case by case;
• the offices have inadequate internet connectivity that cannot be improved in the short term.

Even then, it pays to plan the move: you can start with a group of users or one office and move the others as existing contracts expire.

In short

• An on-premises PBX requires upfront investment, ongoing maintenance and periodic replacement; a hosted PBX is paid for with a monthly fee per user.
• In the cloud, calls always find a way through: forwarding to the mobile apps and redundant data centers, with a 99.999% SLA.
• New users, offices and remote staff can be added in a few steps, with no hardware.
• On-premises hardware only makes sense in a few specific cases.

Want to compare the cost of your current phone system with a hosted PBX? Contact us: we will look at your situation together and suggest the most suitable setup.