Key takeaways:
- A telephone entry system lets visitors call a resident, tenant, or staff member from a door or gate so that person can decide whether to unlock the entrance remotely.
- POTS, cellular, IP/VoIP, and video-enabled systems solve the same basic access problem, but each one depends on different infrastructure, recurring services, and site conditions.
- Legacy landline call boxes may still work for simple properties, but aging hardware, directory-management limits, and POTS dependence often make modern video intercoms worth evaluating.
If a visitor can scroll a directory at your front door, call a resident, and get buzzed in, your property is using some form of telephone entry. The idea is simple: give visitors a way to request access without leaving the door or gate unlocked. The buying decision is less simple, because the technology behind that call can vary a lot.
A telephone entry system is a property access system that lets a visitor contact a resident, tenant, or staff member from an entrance and receive remote approval to unlock a door or gate. Some systems still use traditional landlines. Others use cellular service, Ethernet, VoIP calling, or video-enabled intercom hardware. Those differences affect installation, reliability, recurring costs, directory updates, visitor verification, and how well the system fits with other access points across the property.
So, choosing a telephone entry system is not just a question of replacing the box at the entrance. It is a decision about what your property can support today and what it may need next: basic audio calling, easier management, mobile access, visual verification, or a more connected approach to doors, gates, elevators, and package areas.
This guide will answer:
- What is a telephone entry system?
- How telephone entry systems work
- Types of telephone entry systems
- Telephone entry system costs
- Pros and cons of telephone entry systems
- 5 telephone entry system options
- The POTS sunset and legacy systems
- How to choose the right system for your property
- Telephone entry vs. video intercom
- FAQs
Learn more about telephone entry systems:
What is a telephone entry system?
A telephone entry system is a type of access control used at a building entrance, gate, or controlled door. It lets a visitor find the right contact, place a call through the entry panel, speak with that person, and receive remote approval to enter.
Most systems include a few core parts: an entry panel or base station, a directory, a communications path, release hardware for the door or gate, and a power source. The person receiving the call may answer on a resident phone, desk phone, in-unit station, mobile device, or app-based interface, depending on the system.
The term can describe both older landline call boxes and newer cellular, IP, or video-enabled systems. That is why buyers often see related terms such as call box, gate entry system, apartment intercom, door entry system, and video intercom. They all deal with visitor access, but they differ in how they connect, what they can verify, and how much control they give the property team.
How telephone entry systems work
A telephone entry system works by connecting a visitor at the entrance with someone who can approve or deny access. The exact technology changes by system type, but the basic call flow is usually the same.
- A visitor arrives at the door or gate and uses a directory, keypad, or touchscreen to find a resident, tenant, or staff contact.
- The system places a call through its communications path, such as a POTS line, cellular connection, or IP/VoIP network.
- The recipient speaks with the visitor through two-way audio. In video-enabled systems, the recipient may also see the visitor.
- If access is approved, the recipient sends a release command to unlock the door or open the gate.
- The release hardware activates, usually through a relay connected to an electric strike, maglock, or gate operator interface.
That communications path matters because it shapes both the visitor experience and the installation. A landline call box depends on a copper telephone line. A cellular call box depends on strong LTE or 5G service at the entrance. An IP or VoIP system depends on a reliable network and proper setup.
The release hardware matters just as much. An electric strike controls the latch side of the door, while a maglock uses magnetic force to hold a door closed until the control logic releases it. Installers and property teams also need to understand fail-safe and fail-secure behavior, especially when the door affects egress, fire safety, or local code requirements. Those details should be reviewed with qualified installers and the appropriate local authority when needed.
Key components that shape performance
Two entry panels can look similar from the sidewalk and still perform very differently. The difference is often in the components around the panel.
- Entry panel or base station: The device visitors use to start the call.
- Directory: A printed, keypad-based, or digital list that helps visitors find the right contact.
- Communications path: The landline, cellular, or IP connection that carries the call.
- Door or gate release hardware: The lock, relay, gate interface, or operator connection that grants entry.
- Power: A traditional power supply or, in some IP systems, PoE, which means Power over Ethernet.
- Receiving endpoint: A resident phone, desk phone, in-unit device, or mobile app.
If one part is poorly matched to the site, small issues can become daily frustrations. A directory that is hard to update creates extra staff work. Weak cellular coverage can make calls unreliable at a remote gate. A network that is not ready for IP traffic can create quality issues for VoIP or SIP calling. Door hardware that is not compatible with the new panel can turn a simple replacement into a larger retrofit.
Types of telephone entry systems
Most properties compare four main categories: POTS or landline systems, cellular systems, IP or VoIP systems, and video-enabled systems. None is automatically best. The right fit depends on the property’s wiring, network access, entry layout, security needs, and appetite for recurring service costs.
The table is a starting point, not a final answer. Exact costs vary by hardware, installer, region, and project scope. Recurring expenses can also change the long-term value of a system that looks less expensive upfront.
POTS or landline call boxes
POTS stands for Plain Old Telephone Service. In a traditional POTS telephone entry system, the entry panel uses a copper phone line to place calls. This approach is familiar, and in some older buildings it may work with existing wiring and hardware. If a property needs short-term continuity and wants to avoid a larger retrofit right away, a landline call box may seem like the simplest option.
The tradeoff is long-term dependence on aging telephone infrastructure. A POTS-based entry system can carry ongoing line costs, may rely on hardware that is getting harder to support, and can make future planning difficult when a critical access point is tied to legacy service.
Cellular telephone entry systems
A cellular telephone entry system uses LTE or 5G service instead of a traditional landline. That can be useful at remote gates, perimeter entrances, and other locations where running network cabling would be difficult or expensive. For some gated communities, that flexibility is the main appeal.
Cellular systems still need careful planning. The signal should be tested at the exact installation location, not just elsewhere on the property. A strong signal near the leasing office does not necessarily mean the same signal will be reliable at a gate, garage entrance, or perimeter access point. Cellular service also adds a recurring carrier cost that should be compared with POTS line costs, IP network costs, and any cloud-management fees.
IP and VoIP telephone entry systems
IP telephone entry systems connect through Ethernet and use VoIP or SIP calling to carry voice communication over the network. They often fit properties that already have reliable network infrastructure and want easier administration, more flexibility, or room to expand.
The added flexibility comes with network requirements. Installers may need to review cabling, switch capacity, VLAN design, QoS settings, power availability, and whether PoE is appropriate for the installation. If the network is unreliable or poorly planned, call quality and system confidence can suffer even when the entry panel itself is capable.
Video-enabled systems
Video-enabled telephone entry systems add a camera to the basic call-and-release function. In many cases, this category overlaps with modern video intercom systems. The visitor still starts contact from an entry panel, but the resident or staff member can see who is there before unlocking the door or gate.
That visual context changes the decision for many properties. Audio-only calling may be enough for simple visitor traffic, but video can help residents or staff evaluate deliveries, service providers, and unfamiliar guests. Many modern video-enabled systems also support mobile answering, remote administration, cloud-based directory updates, audit logs, and connection to other controlled access points. They are not the right choice for every site, but they often become a stronger option when a property is already questioning whether a legacy call box still fits.
Telephone entry system costs
The cost of a telephone entry system is more than the price of the panel. A practical budget should separate hardware, installation, and recurring service, because those three categories affect each system type differently.
Hardware costs
Hardware costs depend on what the property needs at the entrance. A basic audio call box, touchscreen directory, video-enabled panel, and multi-entry system can all have different cost profiles. Door and gate hardware also matters. Existing locks, relays, maglocks, electric strikes, or gate operator interfaces may need to be reused, adapted, or replaced.
Installation costs
Installation costs depend on the site. A one-for-one replacement at a single entrance is usually less complex than a multi-entry upgrade across a large property, but even a simple retrofit requires checks for power, mounting, wiring, network reach, signal strength, and release hardware compatibility. Remote gates, older buildings, mixed-use sites, and properties with several user groups can add planning and labor.
Recurring service costs
Recurring costs are where two systems with similar upfront prices can become very different over time. A POTS system may require an ongoing phone line. A cellular system usually requires carrier service. An IP or cloud-managed system may include software or service fees tied to connectivity, remote administration, or hosted directory tools.
That is why total cost of ownership matters. If an older system depends on a copper line and frequent service calls, replacement may be worth evaluating before the hardware fails completely. On the other hand, a property with simple access needs, stable infrastructure, and a supported system may decide that a limited repair or modest upgrade is enough for now.
Pros and cons of telephone entry systems
Telephone entry systems remain common because they solve a real access problem: visitors can request entry without a staff member standing at the door or gate. The question is whether the system gives your property enough visibility, control, and flexibility for the way people actually use the entrance.
Where telephone entry still works well
- Residents, staff, and many installers are familiar with basic call box behavior.
- Audio-based calling may be enough when visitor traffic is simple and low risk.
- Some legacy systems are practical to maintain when the property needs continuity during a budget cycle or renovation plan.
- Smaller sites with few entry points may not need advanced visitor management tools.
For example, an older property with one main entrance and a stable resident list may be able to keep using a basic call box if the system is still supported and the property does not need video verification, remote directory management, or broader access-control integration.
Where the limits become hard to ignore
- Audio-only systems cannot show who is actually standing at the entrance.
- Older directories may be slow to update, which creates extra work when residents, tenants, or staff change often.
- Some systems offer limited audit logging, making it harder to review access activity after an issue.
- Standalone entry panels may not coordinate well with gates, elevators, package rooms, garages, or multiple buildings.
Those limits matter most when staffing is lean, turnover is high, or visitor traffic is too complex for simple voice calls. Student housing may need frequent directory updates. Commercial buildings may need visitor entry to work alongside credential permissions. Senior living communities often need a system that is clear and easy to use, not just technically capable. In each case, the same telephone entry category can feel very different in daily operation.
5 telephone entry system options
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
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.
The POTS sunset and legacy systems
If your property still uses a landline call box, the main question is not only whether it works today. It is how long it will remain practical to maintain. POTS-based telephone entry systems rely on copper telephone infrastructure, and many owners now treat that dependence as a planning risk rather than a stable long-term assumption.
The practical issue is clear even without relying on exact retirement dates: a legacy telephone entry system can become harder to support if it depends on aging communications infrastructure, rising line expenses, or hardware that is difficult to repair. For many properties, the decision shifts from, “Can we keep this running?” to, “Is it still smart to keep investing in it?”
When repair may still make sense
Repair can still be the right move when the system is functional, access needs are simple, and replacement is not yet budgeted. A small property in the middle of a larger renovation cycle, for example, may choose a temporary repair while planning a broader upgrade later.
When replacement becomes the smarter path
Replacement deserves a closer look when the system fails repeatedly, the phone-line dependency is getting harder to justify, directory updates are cumbersome, or the property wants capabilities the legacy box cannot reasonably deliver. Those capabilities may include mobile answering, video verification, cloud-based directory management, remote administration, audit logs, or coordination with other controlled access points.
This is where ButterflyMX can fit naturally for properties evaluating modern alternatives. A ButterflyMX video intercom supports smartphone-based visitor calls, avoids dependence on traditional, soon to be retired POTS lines, and gives property teams remote tools for managing directories and entry activity. For a building already debating whether to keep repairing a landline call box, that type of upgrade can address the replacement need while also improving how the property handles everyday visitor access.
That does not mean every POTS system should be replaced immediately. It means the next repair decision should include the full picture: remaining hardware life, line dependence, recurring service costs, resident expectations, staff workload, and whether the next dollar spent on repair would be better spent on a system with a longer useful horizon.
How to choose the right system for your property
The best telephone entry system for one property can be the wrong fit for another. Start with the site, then look at daily operations, then decide what kind of visitor experience and management model you need.
Start with property type and entry layout
Multifamily apartment buildings often need efficient directory management because resident turnover can create frequent updates. Gated communities may favor cellular systems when entrances sit far from the main building network. Commercial buildings often need stronger access-control integration because visitor entry is only one part of a larger credential and permissions structure. Mixed-use properties may need to serve residents, employees, delivery drivers, guests, and commercial visitors without making the directory or call flow confusing.
Senior living communities should pay close attention to ease of use. That includes how clearly the directory is presented, how simple the answering process feels, and whether staff can help manage visitor access without awkward manual workarounds. Student housing often needs fast updates and manageable turnover processes because resident rosters can change frequently.
Assess your existing infrastructure honestly
Before choosing a system type, confirm what the property can actually support. Check whether the current system depends on a copper phone line, whether network cabling reaches the entrance, whether PoE is available, whether remote gates have usable cellular coverage, and whether existing locks or gate hardware can interface with the new panel. Also review backup power needs, since outage behavior depends on the system design.
If you are considering an IP system, network readiness means more than having an internet connection somewhere on site. It can include reliable connectivity, appropriate switch capacity, power planning, and thoughtful handling of VoIP or SIP traffic. If you are considering cellular, signal testing at the exact entrance matters more than a general coverage map or assumptions about nearby service.
Decide how much capability you really need
Some properties only need basic visitor calling and remote release. Others need stronger identity checks, remote administration, audit logs, or coordination with other access points. If your team is already managing doors, gates, elevators, package areas, or multiple buildings, it may make sense to choose a system that fits into a broader access control approach instead of treating the front entrance as a separate tool.
This is also where the audio-versus-video decision becomes clearer. If residents or staff need to confirm who is requesting entry, or if the property wants a more mobile-friendly way to handle visitor calls, a video intercom may be a better fit than a basic audio call box.
Questions to ask vendors before buying
- What communications path does the system use: POTS, cellular, IP, VoIP, or a hybrid approach?
- What recurring services, carrier plans, software fees, or subscriptions are required?
- How is the directory updated, and who can manage those changes?
- What happens during a power loss, internet outage, or cellular service issue?
- Can the system work with existing door locks, gate hardware, relays, or operator interfaces?
- What audit logging or entry-event visibility is available?
- Can the system coordinate with other access points, such as gates, elevators, package rooms, or additional doors?
- Which parts of installation timing and complexity depend on site conditions?
These questions move the conversation beyond a feature list. They reveal whether a system fits the property operationally, not just whether it can be installed.
Telephone entry vs. video intercom
A video intercom serves the same core purpose as a telephone entry system: it helps a property control visitor entry at a door or gate. The difference is that a video intercom adds visual verification and, in many modern systems, a more flexible way to manage access.
Traditional telephone entry is usually built around audio. A visitor selects a contact, places a call, and asks for entry. That can work well in straightforward settings, especially when cost, familiarity, and simple calling matter more than added visibility. But audio alone limits the recipient’s ability to confirm who is actually at the entrance.
A video intercom adds that missing context. Residents or staff can see the visitor before granting access, which can be useful for deliveries, unfamiliar guests, service providers, and high-traffic entrances. Many video intercom systems also support smartphone-based visitor calls, which can be more practical than routing every interaction through legacy telephone infrastructure.
The difference also extends beyond the call. Modern video intercom systems often make it easier to update directories remotely, review entry activity, and coordinate visitor access with other parts of the property. In the right environment, that may include doors, gates, elevators, and package room access under a more consistent administrative model. The elevator itself is not being replaced; rather, visitor or credential permissions can be coordinated with elevator access controls where the property design calls for it.
ButterflyMX is most relevant in this comparison for properties that want visual verification, mobile access, cloud-based directory management, and a more connected way to manage entry. If your main need is a simple call box and your existing setup still fits, traditional telephone entry may be enough. If your property has outgrown audio-only access, a ButterflyMX video intercom is a natural alternative to evaluate.
Frequently asked questions
Do I need a landline for a telephone entry system?
No. Some legacy telephone entry systems require a traditional landline, but many newer systems use cellular or IP connectivity instead. If you are replacing an older call box, confirm whether the current setup depends on a copper phone line before deciding whether to repair it or move to a different system type.
What happens if the power or internet goes down?
It depends on the system design. Power loss can affect any entry system unless backup power is in place, and IP-based systems also depend on network availability. Cellular and landline-based systems have different dependencies, so outage behavior should be reviewed based on the panel, power design, connectivity method, and release hardware at the property.
Can a telephone entry system integrate with access control?
Yes, some telephone entry systems can integrate with broader access control, but the level of integration varies by platform and installation. A basic call box may only handle visitor communication at one entrance, while more advanced systems may coordinate doors, gates, elevator permissions, or other managed entry points.
How long does telephone entry system installation take?
Installation time varies by site. A simple replacement at one entrance may move faster than a multi-entry upgrade that involves new wiring, network preparation, or hardware changes. The main factors are the number of entrances, existing infrastructure, release hardware compatibility, and whether the property is retrofitting a legacy system or installing a new one.
A telephone entry system is only as useful as its fit with the property. For some sites, a straightforward audio call box still handles visitor access well. For others, especially properties dealing with aging landline systems, frequent directory updates, or higher expectations for remote access, a video intercom may be the more practical next step.
If you are weighing repair against replacement, ButterflyMX can help you compare the tradeoffs and evaluate whether a modern video intercom makes sense for your building, gate, or community. Talk with ButterflyMX about the right entry solution for your property.
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