Telephone Entry Systems: How They Work, Cost, and Modern Alternatives

 

 

Telephone entry systems have long been a familiar way to manage building access. By letting visitors call residents or staff from an entry panel, these systems offered a simple way to grant access without needing on-site personnel at the door.

But many older telephone entry systems were built to rely on POTS, or plain old telephone service, through traditional copper phone lines. Now that major carriers are moving away from supporting that legacy infrastructure and pushing buildings toward VoIP or fiber-based service, many property owners and managers are being forced to rethink whether their current system is still the right fit.

In this post, you’ll learn how telephone entry systems work, why POTS-dependent systems are becoming harder to support, and what to consider if you’re ready to upgrade to a more modern solution.

This post covers:

• What is a telephone entry system?
• How telephone entry systems work
• Types of telephone entry systems
• Why POTS-based entry systems are being phased out
• 5 telephone entry systems
• Cons of telephone entry systems
• When to upgrade from a telephone entry system
• A better alternative to your telephone entry system
• Telephone entry system FAQs

 

What is a telephone entry system?

A telephone entry system is a type of property access system that lets visitors call a resident, tenant, or staff member from an entry panel at a door or gate. Once the call is answered, the person receiving it can speak with the visitor and grant access remotely.

These systems are commonly installed at apartment buildings, gated communities, commercial properties, and mixed-use buildings. In many cases, they include a directory, keypad, and built-in door release function, giving visitors a simple way to find the right person and request entry without needing a front desk or on-site staff member to assist them.

Traditional telephone entry systems were designed around phone-based communication. That means the entry panel places a call to a resident’s landline, mobile phone, or office phone, allowing them to verify the visitor and unlock the entrance. While that setup was once a practical solution, many older systems depend on aging phone infrastructure that is becoming harder for buildings to maintain.

 

What is a POTS telephone entry system?

A POTS telephone entry system is a telephone entry system that relies on plain old telephone service (POTS) to place calls from the entry panel to residents, tenants, or staff. In other words, instead of using internet-based communication, it runs through traditional copper phone lines.

For many years, POTS-based systems were a standard choice for apartment buildings, gated communities, and commercial properties because they offered a simple, familiar way to manage visitor access. When a visitor entered a unit number or selected a name in the directory, the system would call the resident’s phone, allowing them to speak with the visitor and unlock the door or gate remotely.

While this setup was once reliable and widely available, many POTS telephone entry systems now depend on aging infrastructure that carriers are phasing out. As a result, buildings with older systems may need to decide whether to keep patching a legacy setup or upgrade to a more modern access control solution.

 

How telephone entry systems work

A telephone entry system connects visitors to residents through a phone call that can control the building’s door lock. In many older buildings, that call is placed over POTS, or plain old telephone service, using traditional copper phone lines. In newer setups, the call may go through a cellular or VoIP connection instead.

Here’s a step-by-step look at how the process typically works:

• Visitor finds resident in directory. When a guest arrives at the building, they use the telephone entry panel to locate the resident they’re visiting. This is usually done by browsing a printed or electronic directory and selecting the correct unit number or name.
• System places a call. Once the visitor selects a resident, the system automatically places a call to that person’s registered phone number. In a traditional setup, this call is often made over a POTS line. That phone connection is what allows the entry panel to communicate with the resident.
• Resident verifies visitor by voice. When the resident answers the call, they can hear the visitor through the intercom. Traditional telephone entry systems do not include video, so verification is done by voice alone, meaning residents can confirm identity only through audio.
• Resident unlocks door via keypad/tone command. If the resident wants to grant access, they send a command back over the call. In most systems, this is done by entering a specific tone (often pressing “9”) on their phone’s keypad, which signals the entry system to release the door lock.
• Door strike/mag lock releases. Once the unlock command is received, the door strike or magnetic lock disengages, allowing the visitor to enter. Traditional telephone entry systems typically log only basic events (such as call and unlock actions) and do not capture rich data like video or detailed access logs.

This is why the phone connection matters so much. If your telephone entry system relies on POTS, its performance depends on continued support for that legacy phone infrastructure. As more carriers move buildings away from copper lines and toward VoIP or fiber-based service, many property owners are finding that older telephone entry systems are becoming harder to maintain.

 

Types of telephone entry systems

Originally, apartment telephone entry systems were designed for landline phones. But now that cellular towers are everywhere, newer entry phone systems have started offering cellular connections. As technology advances, other features are being added to phone entry systems.

As a result, there are a few different types of entry systems.

Some of the most common types of systems include:

• Landline systems
• Cellular telephone entry systems
• Telephone entry systems with cameras
• Wireless telephone entry systems
• VoIP telephone door entry systems

 

Learn more about telephone entry systems:

 

Landline systems

The first systems were introduced in the time before cell phones, when you had to connect your telephone to a phone jack in the wall. They were designed to let visitors alert residents of their arrival, and let residents unlock the front door without going downstairs.

When receiving a call placed through the telephone entry model, residents with landline phones answer it just like they would a normal phone call. They can hear and speak with their visitor. To unlock the door for their guest, they simply press ‘9.’

 

Cellular telephone entry systems

Until recently, these systems required a dedicated phone line. But landline phones are dying out — as of now, only 68.9 million people have a functional landline. To adapt, many providers have started connecting their telephone entry models through a cellular service (e.g Verizon, AT&T, T-Mobile, etc.)

However, many cellular entry systems require customers to purchase and install a cellular connection box to enable cell service. And since most cellular-enabled systems aren’t cloud-based, they can’t offer features like video calling, delivery PINs, or a mobile app.

 

Telephone entry systems with cameras

These days, multifamily residents demand tech-powered apartment amenities. Recognizing that these systems can’t meet that demand, some access control providers have started adding cameras to their tele entry systems.

Adding a camera to a telephone entry model improves security at the building by offering residents a way to see visitors and speak with them. A modern telephone entry systems with camera offers in-unit hardware with screens to display video footage. Others have started developing mobile apps where residents can view video footage of visitors from their smartphones.

 

Wireless telephone entry systems

A wireless telephone entry system enables communication between visitors and residents without the wiring required of traditional systems with phone lines. As such, most wireless phone entry systems operate with cellular networks.

Remember: You’ll need to pay for a cellular service plan to enable calls from a wireless entry system. So, you’ll have to factor that monthly expense into your budget.

 

VoIP telephone door entry systems

A VoIP telephone entry system uses VoIP technology for voice communication rather than POTS telephone lines. VoIP stands for ‘voice over internet protocol.’ These systems transfer data over the internet rather than telephone wires.

VoIP phone entry systems require an internet connection and possibly TCP/IP and VoIP adaptors.

 

Why POTS-based entry systems are being phased out

For years, POTS-based telephone entry systems gave buildings a simple way to manage visitor access. But many of those systems were built to rely on traditional copper phone lines, and that infrastructure is becoming harder to support as carriers continue shifting customers to newer fiber and IP-based networks. The FCC has published guidance on these technology transitions and copper retirements, which is why more buildings are now being told their legacy phone service may be changing.

That matters because a POTS-based entry system depends on that phone connection to work the way it was originally designed. If the underlying service changes, property owners may be forced to look at adapters, workarounds, or system updates just to keep an older setup running. In many cases, that means putting more time and money into a system that still lacks the convenience, flexibility, and features of a modern access solution.

For many buildings, this shift is more than a telecom issue. It is a sign that the old way of managing entry is reaching its limit. Rather than patching a legacy system that relies on aging infrastructure, many properties are using this moment to upgrade to a modern platform that is easier to manage and better suited for today’s residents, staff, and visitors.

 

5 telephone entry systems

If you intend to purchase a telephone entry system, make sure you choose one that is worth the money.

Here are five telephone entry models to consider:

1. Doorking
2. Kantech
3. Mircom
4. Linear
5. Select Engineered Systems

 

1. Doorking

 

Doorking is perhaps the most well-known telephone entry system provider in the industry. Based in Southern California, Doorking (or DKS) has sold phone entry systems since 1948.

DKS telephone entry models have a traditional, simple design with few features or bells and whistles. These systems are installed on POTS phone lines, requiring traditional telephone wiring. However, Doorking does offer cellular telephone entry models. But to enable cellular service, you must purchase the DKS Cellular Connection Box, which is sold separately from the entry system.

Features of Doorking systems vary by model but may include:

• LED tenant directory
• Ability to store thousands of names and phone numbers
• Programmable via PC (systems include programming software)
• Tamper alert switch
• Weather sealing

According to a January 2022 price sheet, Doorking systems’ hardware costs from $1,496 to $7,040 (depending on model).

Remember to also budget for installation fees and possible service connection costs. A VoIP adapter costs $180, while cellular service connection plans range from $1,200 to $1,700.

 

2. Kantech

 

Kantech is a Tyco Security Products company founded in 1986 that designs and sells various access control solutions that are ready to use right out of the box. The company’s product lineup ranges from security services and software to door controllers and telephone systems.

The Kantech Telephone Entry System (KTES) is a basic building entry system designed for apartments, gated communities, condos, offices, and industrial properties. Visitors can call and communicate with a tenant directly through the KTES, at this point, the tenant can grant or deny entry directly from a landline telephone or cell phone.

Property staff can remotely manage their building’s KTES using Kantech’s EntraPass software, which appears to be sold separately and may only be compatible with Windows operating systems.

Features of the Kantech telephone entry system:

• Compatibility with Kantech door controllers.
• Comes with a pared-down version of EntraPass management software. So, you may have to purchase the full software package for access to all features.
• Use as a stand-alone system or integrate with an existing access control system.
• Vandal- and weather-resistant stainless steel casing.
• One phone line supports up to five units.
• 4-line, 20-character LCD screen.
• Directory capacity of 3,000 tenants.

 

3. Mircom

 

Founded by Tony Falbo in 1991 and based in Canada, Mircom is a security and building solutions provider that offers a variety of TCP/IP ready, auto-dial, and NSL (no subscriber line) telephone entry models.

Mircom’s telephone entry system product lineup includes:

• Paper directory systems
• Hands-free electronic directory models
• Slim-line models
• Video telephone access system
• NSL telephone access kits (for buildings without a dedicated phone line or that don’t want to pay for a dedicated phone line)

Mircom phone entry systems are basic property entry solutions designed for apartments, condos, gated communities, offices, and industrial sites.

Mircom system features:

• Option to add key card access and elevator controls
• Electronic or paper directory, depending on the model
• Programmable via the built-in keypad or with a computer via optional TX3 configuration software
• Require a dedicated phone line (for NSL configuration, you’ll need additional hardware such as relay cards and relay cabinets)

Mircom telephone system pricing doesn’t appear to be available on the company’s website, so you may have to contact them to request a quote.

 

4. Linear

 

Founded in 1961, Linear is a well-known access control solutions provider based in Carlsbad, California. The company is part of the Nortek Control family of brands, offering a variety of products including door operators, access control devices, and telephone entry systems.

Linear telephone entry systems can be programmed locally using the system’s keypad. But remote management and programming vary by model. For example, the AE-100 can only be programmed remotely via a touch-tone telephone. But the EP-402 may be fully browser-managed.

Features of Linear tele entry systems:

• Built-in keypad on all models
• Electronic directory with navigation buttons (plus one touchscreen model)
• Number of doors supported varies by model (1-, 2-, or 36-door models)
• Most basic model allows up to 125 tenants; other models may have greater directory capacity
• Accessories sold separately, including add-on camera, metal trim rings, and pedestal mounts.

 

5. Select Engineered Systems

 

Select Engineered Systems (SES) develops and offers cost-effective, scalable access control solutions. The company was founded in 1976 but incorporated as Select Engineered Systems in 1980, and is today based in Florida.

SES offers various products, including help communication systems, card entry systems, building communication systems, and digital keypads. However, it primarily focuses on tele-entry systems.

Select Engineered Systems offers two system models: the TEC1 basic and TEC2 series.

SES telephone entry system features:

• 2-, 4-, or 10-line LCD display
• Five tenant directory capacities: 50, 125, 250, 500, or 995
• Two-year limited warranty
• SELCOM software can be used to enter data, create databases, configure access control parameters, and set timed access schedules.

 

Cons of telephone entry systems

Traditional telephone entry systems can still provide basic visitor access, but they often create more work, less flexibility, and more long-term uncertainty for today’s properties. That’s especially true for older systems that rely on POTS or other legacy phone infrastructure.

Telephone entry models have a few limitations that you should consider:

• They require a telephone line to make outgoing calls. This means you’ll have to pay a monthly fee for that line. It also means that if your resident has an out-of-state phone number, your system will be making a long-distance call to that resident even though they live in your building. These costs add up quickly.
• You can’t manage a telephone entry model remotely. For example, adding a tenant to the directory requires you to go onsite and program that person into the system. The same is true if you want to remove that resident. This is a highly time-consuming process when you factor in your average turnover rate and the time it takes to travel to each building you own or manage.
• They lack cameras. Since the data required to transfer video is too large for a telephone line to carry, these systems cannot have built-in cameras. As a result, residents and building staff can’t see who they’re letting into the building.

Thankfully, technology has improved significantly since the invention of the entry system. Today, we have better entry solutions available.

 

When to upgrade from a telephone entry system

A telephone entry system may still seem “good enough” until it starts creating more work for your team, more frustration for residents, and more risk for your property. If your current system depends on aging phone infrastructure or no longer supports the way your building operates today, it may be time for an upgrade.

Common signs it’s time to move on include:

• Your system relies on POTS or a traditional copper phone line
• You’re being pushed toward adapters, converters, or temporary fixes
• Directory updates and resident turnover create too much manual work
• Residents no longer want to rely on call-based entry
• You need stronger security and better visibility
• Deliveries and visitor access are still causing friction
• Your team needs a system that is easier to manage remotely

 

Your system relies on POTS or a traditional copper phone line

Many older telephone entry systems were built around POTS. If your provider has told you that service is being phased out or moved to a newer network, it may no longer make sense to keep investing in a legacy setup.

 

You’re being pushed toward adapters, converters, or temporary fixes

If keeping your current system running requires workarounds just to maintain basic functionality, that’s often a sign the technology is reaching its limit.

 

Directory updates and resident turnover create too much manual work

Legacy systems can make even simple changes time-consuming. When move-ins, move-outs, and staff updates require constant manual reprogramming, your team loses time that could be spent elsewhere.

 

Residents no longer want to rely on call-based entry

Traditional telephone entry systems were designed around call-based access. But today’s residents expect a more convenient experience, especially one that works from their smartphone.

 

You need stronger security and better visibility

Audio-only verification can make it harder to confirm who is requesting access. If you want video, better audit trails, and more control over entry activity, an older telephone entry system may be holding you back.

 

Deliveries and visitor access are still causing friction

If staff and residents are dealing with missed deliveries, unnecessary interruptions, or inconsistent guest access, your entry system may no longer match the needs of a modern property.

 

Your team needs a system that is easier to manage remotely

When on-site staff is limited, managing outdated hardware becomes even more difficult. A modern solution can help your team oversee access from anywhere without depending on legacy infrastructure.

 

A better alternative to your telephone entry system

If you’re evaluating whether to keep your existing telephone entry system or upgrade to something more modern, it’s worth considering what today’s properties actually need from an access solution.

ButterflyMX’s Video Intercom is a modern alternative to the traditional telephone entry system. Instead of relying on audio-only calls and basic door release, it combines video, mobile access, and cloud-based management into a single platform designed for both residential and commercial properties.

Founded in 2014, ButterflyMX’s Video Intercom system provides property owners, managers, and residents with a mobile app to open doors, gates, and elevators. While traditional telephone entry systems can improve security, they offer little more beyond that. You’re better off with a video intercom that enhances security and convenience for residents and property staff.

ButterflyMX vs. traditional telephone entry systems:

Feature	ButterflyMX Video Intercom	Traditional telephone entry system
Built-in wide-angle camera	Yes	No
Mobile app	Yes	No
Remote system management	Yes	No
Cloud-based software	Yes	No
Video calling	Yes	No
Visitor Passes & delivery PINs for managed visitor access	Yes	No
Easy installation	Yes	No
Audit trail of door entry events	Yes	No
Integrations with other technology	Yes	No
WiFi present in the device	Yes	No

 

Telephone entry system FAQs

• How do I know if my telephone entry system relies on POTS?
• What should I do if my POTS telephone entry system is no longer supported?
• How do you use an entry phone?
• How much does a telephone entry system cost?
• Do telephone entry systems require a landline?

 

How do I know if my telephone entry system relies on POTS?

Your telephone entry system may rely on POTS, or plain old telephone service, if it uses a traditional copper phone line to place calls from the entry panel to residents or staff. In many older buildings, that phone connection is what allows the system to call a resident, verify a visitor by audio, and receive the keypad command that unlocks the door.

A few common signs your system may be POTS-based include receiving service notices from your phone provider, relying on a dedicated landline for the entry panel, or using an older call box that was installed before internet-based entry systems became common. If your provider has told you that your building’s copper line is being retired or transitioned to newer service, that is a strong sign your existing setup may no longer be supported long term.

In that case, it may be time to consider upgrading to a modern access control system that does not depend on legacy phone infrastructure.

 

What should I do if my POTS telephone entry system is no longer supported?

If your POTS telephone entry system is no longer supported, you generally have three options: try to maintain the system with workarounds, move to a VoIP-compatible setup, or upgrade to a modern access control platform. For many properties, upgrading is the better long-term choice because it reduces dependence on aging infrastructure while adding features like video calling, remote management, and smartphone-based access.

The cleanest next step in the blog is probably revising the FAQ section as a group so all the new POTS-related questions work together.

 

How do you use an entry phone?

To use an entry phone as a visitor, you simply contact a tenant and have them grant access. To use an entry phone as a tenant, you can verify the guest’s identity, then press ‘9’ on the keypad to grant entry.

 

How much does a telephone entry system cost?

These systems cost between about $1,000 and $7,000, not including installation or maintenance fees.

Hardware costs vary based on the system’s functionality. For example, basic phone entry systems that lack many features and limit the number of tenants you can add may sell at the lower end of the price range. In contrast, a more modern cellular door entry solution will cost more.

 

Do telephone entry systems require a landline?

No, telephone entry systems do not always require a landline. While older systems were designed to operate over traditional POTS phone lines, many modern models use cellular networks or VoIP (internet-based) connections instead. The required connectivity depends on the type of system installed at the property.

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