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What Are Multi-Line Phone Systems?

Updated Feb 21, 2023

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For most businesses, it is imperative to have a business phone system that can handle more than one call at a time. When you have multiple employees, you need them to be able to make or accept calls when they need to, regardless of whether someone else is also on a call. You never want customers to get a busy signal when more than one is trying to call your business simultaneously, either. That’s why most businesses need some form of multi-line phone system. 

What is a multi-line phone system?

A multi-line phone system is any telephonic connection that allows the simultaneous use of two or more lines. In fact, you probably already have one. Many mobile phones already support multiple lines to hold calls, switch between callers, and have a conference for up to three people. But what happens when you need more lines to support a larger workforce? 

That’s when the situation becomes a bit more complicated. But it also may be your ticket to help your business become more efficient, especially when you need fast, friendly customer service. With the right kind of multi-line phone system, you can build a private, secure and cost-effective contact center.

Editor’s note: Looking for the right business phone system for your business? Fill out the below questionnaire to have our vendor partners contact you about your needs.

How does a multi-line phone system work?

A multi-line phone system creates a network with individual lines for each employee. This allows you to install dedicated phones for an entire workforce through the existing phone lines at your office building.

>> Learn More: What Is Interactive Voice Response (IVR)?

With a multi-line phone system, you could set up each line with a dedicated number for external parties to call, so a client or customer can reach the specific person they’re trying to contact. The handsets you use for your phone system also make a difference, with some handsets able to support multiple lines on their own, or have multiple lines installed for each phone. Another route is a private branch exchange (PBX) line.

FYIDid you know

With a multi-line phone system, you can either set up each line with a dedicated number or use a private branch exchange (PBX).

With a PBX multi-line phone system, calls are routed through the main line so the office can screen and redirect calls as they come in. A PBX system can be automated, offering specific prompts and extensions to guide callers to the right representatives, while a manual approach allows a receptionist to provide tailored service when pointing clients to the person they’re trying to contact.

>> Learn More: What Is a Cloud PBX?

How do traditional and cloud-based multi-line phone systems differ?

Traditional multi-line phone systems

Because a traditional telephone system relies on physical landlines, it requires a representative or engineer from your local telephone company to install and configure the multi-line system. However, having multiple, dedicated landlines in the same location can become costly, as each line carries an additional fee. [Related article: Choosing a Business Phone System]

Landlines are a necessity for traditional multi-line phone systems, but they come with limitations. Traditional phone lines are generally best for audio-only interactions. As communication technologies advance, the features that a landline can support – like video conferencing or text communications – will become smaller compared to more modern solutions like Voice over Internet Protocol or VoIP

The network might become overloaded for a smaller business with a limited number of lines, preventing your customers from connecting your business. You can use services to put callers on hold while representatives go through the queue, but those options come at an added cost.

Cloud-based phone systems

A cloud-based phone system like VoIP uses the internet to establish a telephone connection, rather than relying on traditional landlines. One benefit of a VoIP system for a small business is that it lowers the cost of communication. Because a cloud-based phone system offers the flexibility to use multiple kinds of devices to make a call, including a desktop or laptop computer, you don’t need to buy dedicated telephone hardware. That keeps your operating expenses down.

TipBottom line

A cloud-based phone system lowers your expenses since you can use your computer or laptop to make calls and don’t need dedicated telephone hardware.

One of the major selling points of a cloud-based system is that you can create new numbers on the fly and scale up the system as your organization grows. All it takes is a few clicks from your system administrator, and you’ll be all set with a new number for each new employee. And because calls can be taken from a computer or even a mobile device, a cloud-based system enables your team to send multiple types of files and messages, even while on the go. 

One of the reasons some businesses still prefer traditional landlines is that any cloud-based phone system relies on a high-speed broadband internet connection. That becomes a problem in remote areas, or regions with spotty or outdated internet services. Even with strong internet service, you could face bandwidth issues that lead to problems with audio fidelity or dropped calls.

Types of multi-line phone systems

Figuring out how many phone lines you need is pretty simple – all you need to do is add up how many employees need a dedicated line, how many shared lines you need, and how many lines you need for fax machines or automated reception services. Once you have that number, look at your options.

2-line phones

A two-line phone system is one of the more common among entrepreneurs creating a business on their own for the first time. Even people working from home are starting to use two-line phone systems so they have a business number that is separate from their personal number. This allows them to both prioritize calls and add a more professional touch for customers and clients.

Two-line phone systems are typically used by contract or gig workers, small offices and businesses, and one-person operations that regularly receive a moderate volume of calls. 

>> Learn More: Understand What is a Virtual Phone Number

4-line phones

Four-line phone systems might be the right choice for a small or midsize business with a dedicated team that works in an office and answers customer calls regularly. If your business has a sales team, along with an accounts payables team or other support personnel, a four-line phone system provides dedicated lines for employees who need them and shared lines or a fax line for the rest of the team. 

Four-line phone systems are also ideal for midsize contact centers and receptionists who must put calls on hold and route them through an office. 

6-line phones and beyond

Once your operation expands further, start looking into a six-line phone system (and beyond). For example, a creative services production agency may need a dedicated phone line for a fax machine, a phone line for the project manager, and a line for each team member to provide quick responses to various requests. As your business grows, so do large-scale multi-line phone systems options. VoIP offers the most scalability. 

Bottom LineBottom line

As your business expands, you may need a phone system with six or more lines. VoIP offers the most scalability for large phone systems.

What features should you look for in a multi-line phone system?

Caller ID

With caller ID included in your multi-line phone system, you can screen any call and see the name and number displayed on your desk phone. This is particularly handy for filtering out spam calls. 

Volume control

Volume control allows you to find a comfortable volume while you’re placing calls.


A voicemail system will help you return any missed calls from customers. 

‘Message waiting’ indicator

It’s easy to forget to check your messages. That’s where a ‘message waiting’ indicator can help. Whether a light on a handset or an icon on a screen, an indicator can ensure your team takes quick action on missed calls. 

Headset compatibility

A headset is a lifesaver when you need to use both hands to assist a customer or take notes during a meeting. Some multi-line phone systems include a physical port on the hardware, but many telephones also have Bluetooth compatibility for wireless headsets. Whichever type you get, a phone that can support a hands-free headset will allow your team to multitask and efficiently support clients or customers.

‘Do not disturb’

When you’re in an important conference call with a key client, interruptions can make or break any deal. You can avoid unnecessary disruptions during a sales pitch when your phone system has a ‘do not disturb feature.

Auto attendant

For busy businesses that receive several calls regularly, an auto attendant feature routes calls from a central number to the right people. 


A phone system with a conferencing feature allows you to talk to multiple people simultaneously. The ability to connect with multiple colleagues and clients located in several regions, all at the same time, is a necessity for larger business discussions. 

Included installation

Sometimes it’s easy to install a phone on your own; sometimes it’s not. Some multi-line phone systems include installation in the price to make sure everything’s connected properly. 

Customer support

Should you ever have a problem with your phone system, make sure you have access to a customer support line to ensure a quick resolution and continuous operation for your business. 

>> Learn More: Types of Phone Systems for Small Businesses

What are the benefits of multi-line phone systems?


VoIP phone services are among the most affordable options for multi-line phone systems. Because traditional phone services depend on landlines, you’ll need dedicated hardware for every line in your multi-line phone system. With VoIP phone systems, that dependence on separate hardware (and the added cost) goes away. 


Multi-line phone systems are flexible and come with options for how many lines you need, along with multiple solutions to help your team quickly answer any incoming calls. There are also options to help your team receive other types of data over the phone, such as emails, texts, and images.


Multi-line phone systems are designed for growth, whether you’re using VoIP or traditional landlines. If you’re with a traditional phone service, you’ll need a representative to come to your office and manually install the new lines. With a VoIP service, you can update the number of lines and activate service from your computer or mobile device. 

Call management

A multi-line phone system can record your call times, call durations, who called you, who you called, and the participants in a conference call. This data allows you to track peak call hours, how long an average support call lasts, and who dialed into a meeting. [Related: Learn about Auto-Dialers]


Multi-line phone systems may offer security features that block spam calls and privacy features to prevent your phone number from getting out in the first place. VoIP phone systems can encrypt your phone calls for added security.

TipBottom line

How do you set up a multi-line phone system?

Setting up a multi-line phone system for your business is fairly straightforward. If you’re opting for a traditional landline service, you’ll need to contact your local phone company to install lines. Traditional systems have the added costs of an onsite PBX and any necessary technicians.

>> Learn More: When Should You Upgrade Your Business Phone System?

With VoIP, you can set up a multi-line phone system in three easy steps:

1. Choose your provider and phone plan. All of the major service providers offer reliable service at competitive rates with a variety of features, so it’s just a matter of picking the provider that appeals to you.

2. Assign phone extensions. Each employee will have their own unique line, and you can assign specific extensions or full numbers to each member of your team. This should only take a few minutes.

3. Start making and answering calls to support your customers, close deals, and catch up with colleagues.

Eduardo Vasconcellos
Contributing Writer at
Eduardo Vasconcellos is a veteran copywriter, creative content producer and marketing communications specialist with over two decades experience, able to take complex concepts and turn them into something simple and memorable. By focusing on customer psychology and product benefits, his specialty is crafting full marketing campaigns that follow industry best practices while authentically speaking to a customer’s need.
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