How Much Does Business Phone Line Installation Cost in 2025?

This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.

Installing a business phone system costs an average of $405, with most people spending between $152 and $673. Your total cost depends on factors like the number of lines you need, the type of system, and any ongoing subscription fees. Proper budgeting is crucial, and hiring a professional ensures that your business communication is set up correctly.

Business Phone Line Installation Cost Factors

There are several factors that can affect the cost of installing a phone system for your business. Below, we'll provide more in-depth information on these cost factors.

Number of Lines

The more lines you have, the more it costs to install a business phone system. This includes hardware costs, as each line requires a phone, but it also takes into account any required subscription costs. Hosted voice over internet protocol (VoIP) providers, for instance, charge an average monthly fee of $15 to $40 per user.

Additionally, some of the systems mentioned above aren't built for large user bases, including KSU-less systems. For VoIP services, additional lines cost up to $50 per month extra per user. For analog systems, adding a secondary line costs about the same as the initial installation, in the range of $150 to $700.

Subscriptions and Licensing

Business phone systems are not a one-and-done affair, so expect to pay monthly subscription fees for each line or user and a yearly licensing fee to access any necessary software. Licensing the software costs an average of $1,000 per year, depending on how large your business is, with VoIP provider subscription fees coming in at an average of $15 to $40 per user.

Using an on-premise VoIP reduces these subscription costs, as does choosing a simple analog system with landlines.

Cost by Business Phone System Type

There is an array of business phone systems to choose from, each with its own price range, advantages, and disadvantages. Some systems are a better fit than others, depending on the business size and unique requirements. The table below shows average price ranges for medium-sized businesses with 50 to 100 employees.

VoIP Phone Systems

Voice over Internet Protocol (VoIP) systems use your internet connection instead of a conventional phone line, helping to keep costs down. There are two main types of VoIP systems: Hosted VoIP and On-Premise VoIP.

Hosted VoIP: With Hosted VoIP, the provider hosts the software on its own servers. You'll pay a monthly subscription fee per user of $15 to $40, as these systems require a robust internet service with increased bandwidth in addition to provider costs. Hosted VoIP systems are popular because they save you the hassle of maintaining hardware, though they increase the monthly subscription fee. You need an active computer network for this service. Installing a computer network costs anywhere from $190 to $690, depending on the size and features.

On-Premise VoIP: With On-Premise VoIP, all the hardware to host the system exists on-site, making the company its own provider. Upfront costs are higher since you’re building a robust network from scratch. However, recurring subscription costs are drastically reduced when compared to hosted systems. You won't pay a per-user monthly fee; instead, there’s just the licensing software fee and the cost to maintain the network.

Private Branch Exchange (PBX) Phone Systems

A PBX (private branch exchange) phone system is a private network installed on-site, similar to an on-premise VoIP. As such, you’ll pay a hefty amount upfront for a medium-sized business. This includes all the hardware to get started, a software license, and the first month's maintenance fees.

The main unit connects all the phones within the organization to the public-switched telephone network (PSTN) and any other third-party providers or trunks. Employees can make phone calls using one of the many outside lines, and the main unit processes all telephone communications in and out of the business.

PBX systems are robust, allowing for private mailboxes, conference calling, in-system private messaging, and much more. Subscription fees are fairly nonexistent, though there’s often a monthly maintenance cost.

Key Service Unit (KSU) and KSU-Less Phone Systems

Key Service Unit (KSU) phone systems are basic multiline offerings ideal for smaller businesses with five to 40 employees. These systems don't offer the features of a PBX system but allow for department extensions and similar functions. Each phone typically includes several buttons that route to each line, making them suitable for smaller businesses.

KSU-less systems work on the same principle as KSU phone systems, but without the main processing box. For this reason, they’re typically one of the least expensive phone system solutions, especially for smaller businesses with fewer than 10 employees. KSU-less systems are adequate for basic business needs, with phones including hold buttons, a speakerphone, paging services, memory dialing, and more.

DIY vs. Hiring a Phone System Installation Pro

It's best to hire a professional to install your business phone system unless you're operating a small business with a simple landline-based system. Hiring a local phone system installer minimizes headaches and ensures everything goes smoothly, as many of these systems are complex. The installation process requires knowledge of electrical systems, wiring, and intricate high-tech components.

The networked components, such as hubs and routers, also require specialized expertise. If you opt for a hosted VoIP, the provider may handle the installation. Call to confirm before activating the service.

How HomeAdvisor Gets Its Cost Data

No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. After a project is complete, we survey real customers about the costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.