What a Home Security System Actually Includes in St. Louis
Revised August 19, 2026
What are the four types of security systems?
The four types most often named for a home are intrusion (burglar) alarms, fire and life-safety detection, video surveillance, and access control such as smart locks and keypads. A second, equally common framing splits them a different way: monitored, unmonitored, wired, and wireless. Both answers are correct, and knowing which one a salesperson means saves you a confusing half hour.
Keep reading ↓Imagine it’s a Tuesday in November and you’re standing in your kitchen in Affton at 6:40 in the morning, coat half on, staring at a keypad the previous owners left behind. It blinks. It has blinked for two years. You have never once known what it’s connected to, whether anybody is watching, or what happens if you punch in a code and get it wrong.
Or maybe you just closed on a place in St. Charles and the seller mentioned, almost in passing, that the alarm is monitored. Monitored by whom? Paid by whom? Nobody at the closing table knew. Meanwhile your brother in Belleville swears by the camera doorbell he put up himself in twenty minutes, and your mom in Florissant has a security sticker in the front window with absolutely nothing behind it.
Here’s what almost nobody explains before you sign anything. A home security system is not one product. It’s a stack of separate pieces — hardware, a way to phone out, a service contract, and a paperwork step with whoever would actually respond — and every layer can be bought, skipped, upgraded or swapped on its own. Once you can name the layers, the sales conversation gets a lot shorter.
What does a home security system actually include?
A home security system includes four working parts plus one optional service. The parts are sensors that detect something, a panel or hub that decides what the sensors mean, a communicator that gets the signal out of the house, and a siren. The optional service is monitoring — a human at a central station who sees your signal and calls somebody. You can buy the hardware without the service.
Sensors are the part people picture. Door and window contacts are two magnets that lose contact when the opening moves. Motion detectors watch a room with infrared and are usually mounted in a corner, aimed across the path someone would walk, not at a window. Glass-break sensors listen for the specific frequency of breaking glass, which matters in older homes with big single-pane basement windows. Smoke and carbon monoxide detectors often ride on the same panel, which is a real advantage: they can bring a signal out of the house even when nobody is home to hear the chirp.
The panel is the brain, and it’s where the arming modes live — away, stay, night, instant. The communicator is the piece buyers forget entirely, and it’s the one that decides whether your alarm can call for help at all. Older systems used the landline. Newer ones use a cellular radio, broadband, or both, with the cell radio as backup. Ask which one you have. The siren is not decoration; a loud interior siren is what ends most incidents before anything else happens.
Cameras, smart locks, video doorbells and garage controllers are add-ons that attach to that stack. They’re useful, and they’re also where a quote quietly doubles. None of them detect an intrusion the way a contact or a motion sensor does — they record it.
What are the four types of security systems?
The four types most often named for a home are intrusion (burglar) alarms, fire and life-safety detection, video surveillance, and access control such as smart locks and keypads. A second, equally common framing splits them a different way: monitored, unmonitored, wired, and wireless. Both answers are correct, and knowing which one a salesperson means saves you a confusing half hour.
The first framing is about what the system is for. Intrusion catches somebody coming in. Life safety catches smoke, carbon monoxide, and in many setups water and freezing pipes — genuinely relevant in a January cold snap in a Kirkwood house with pipes in an uninsulated crawlspace. Video shows you what happened. Access control decides who gets in without a key.
The second framing is about how it’s built and billed. Monitored means a central station receives the signal. Unmonitored, sometimes sold as self-monitored, means the siren sounds and your phone buzzes and that’s the whole plan. Wired systems run cable to every sensor and are typical in homes built or renovated with the system in mind. Wireless sensors run on batteries you will eventually replace, and they’re what makes a 1920s brick two-story in south city practical to protect without opening plaster walls.
What are you actually paying for with monitoring?
Monitoring buys you a person. When a sensor trips, the signal goes to a central station where an operator follows a script: verify the alarm, usually by calling the house and then your contact list, and dispatch police or fire if nobody gives the passcode. That verification step is the whole product. Without it, an alarm signal is a noise in an empty house.
This is where the paperwork you never think about starts to matter. The passcode, the call list, and the phone numbers on file are what stand between a bumped motion sensor and a squad car. The Security Industry Alarm Coalition, the trade group that works with police departments on alarm ordinances, puts the share of false alarms caused by user error at roughly 85 percent. Not faulty equipment. People.
So when you compare monitoring plans, compare the things that actually differ: whether the central station is redundant across two locations, how fast they commit to attempting contact, whether you can update your call list yourself from an app at 11 p.m., and what the contract term is. Ask what happens to the equipment if you cancel — on some plans you own it outright, on others you’ve been leasing it the whole time.
Unrelated, and we know it — the basement clutter fix is a storage unit.
Do you have to register a home alarm in St. Louis?
In the City of St. Louis, yes. Ordinance 66264 requires all security alarm systems to be registered with the city — wireline and wireless, residential and commercial, and monitored and non-monitored. The registration fee is $25 for a residential system and $50 for a commercial one. If your system is monitored, your alarm company normally files it for you rather than you paying the city directly.
The false alarm side has teeth on paper. Under the city program, the first false alarm is free, the second carries a fee, and the charges escalate from there within the same year; enough of them and the city can suspend your permit and stop responding to alarm calls at your address. How well that gets collected is another story. St. Louis Magazine reported on a comptroller’s audit showing past-due false alarm fines of $755,989 as of June 30, 2025, with the comptroller describing the ordinance as having no teeth on the collections end.
Outside the city limits it varies by who answers the call. St. Louis County regulates alarms under Chapter 720 of its revised ordinances, and dozens of individual municipalities in St. Louis, St. Charles, Jefferson and Franklin counties layer their own alarm codes on top. On the Illinois side, St. Clair and Madison county communities set their own rules too. The reliable move is simple: call the non-emergency line of the police department that would actually be dispatched to your address and ask whether they require registration. That one phone call is the whole compliance step for most households.
Who is allowed to install an alarm in Missouri versus Illinois?
Illinois licenses alarm work at the state level; Missouri does not. In Illinois, the Private Detective, Private Alarm, Private Security, Fingerprint Vendor and Locksmith Act of 2004 (225 ILCS 447) requires a Private Alarm Contractor license from the Illinois Department of Financial and Professional Regulation to sell, install, monitor, alter, replace, service or respond to alarm systems. Employees of a licensed contractor generally need a Permanent Employee Registration Card, the PERC.
That means a homeowner in Belleville, O’Fallon or Edwardsville can look up the company and the license in one place. IDFPR moved new Private Alarm Contractor applications into its CORE online system on October 30, 2024, so the record is searchable.
Missouri handles it locally instead. St. Louis County requires an alarm business license under Chapter 720, and the application is referred to the police for annual background checks, with a non-refundable application fee of $415. The City of St. Louis licenses alarm installation and monitoring businesses through the License Collector’s office, and a company that provides monitoring service also needs a communications permit from the Building Division. So on the Missouri side, ask the company which jurisdictions it’s licensed in. A crew that works Chesterfield and Maryland Heights every week may not be licensed in the city itself.
What older St. Louis houses change about the equipment list
Housing stock drives the sensor list more than the brand does. A lot of this metro is pre-1950 brick with a walk-out or grade-level basement, a rear alley, and a detached garage — the pattern you see block after block in Dutchtown, Maplewood, Webster Groves and Granite City. Three things follow from that.
First, the basement is a real entry point, not an afterthought. Grade-level windows and a rear basement door deserve contacts and often a glass-break sensor, and that’s the area walked past on cheap quotes. Second, the detached garage and any outbuilding sit outside most base packages entirely; covering them is a separate line item, and if you’re storing tools out there it’s worth pricing. Third, solid masonry is hostile to retrofit wiring, which is exactly why wireless sensors took over here — but wireless means batteries, and batteries mean a maintenance rhythm somebody has to own.
One more that gets skipped: tie smoke and carbon monoxide detection into the panel if you can. Older furnaces, wall heaters and attached garages are common here, and a monitored CO signal reaches help when the house is empty. If you want a sense of what actually shows up when that signal goes out, our look at what St. Louis fire departments do besides fires is a useful companion read. And if you’re mounting sensors into brick yourself, a rented hammer drill beats a ruined bit — see renting tools and equipment in St. Louis.
Why does every alarm company push the monitoring contract?
Because the contract is the business. Equipment and installation on a residential job are close to a break-even lever; the asset is recurring monthly revenue, and alarm companies are bought and sold as a multiple of that recurring base. Attrition is the number owners actually track. That’s also why the seasonality runs the way it does: spring and summer moving season fill the install calendar, a break-in on a nearby street fills it faster, and January and February are quiet enough to hurt.
What customers get wrong is the call list: stale numbers, a forgotten passcode, an ex-roommate still listed as a contact. The good operators rebuild that list at every service visit and file the customer’s registration for them. And when the carriers retired their 3G networks in 2022, shops across this metro spent months swapping perfectly good radios, explaining a bill nobody expected. Owners in this trade know the demand is local and search-driven, which is why being listed, licensed and easy to find at St Louis Near Me Directory is part of the job now.
Want a real quote instead of a sales pitch? Browse security systems companies across the St. Louis metro on St Louis Near Me Directory, then ask three of them for an itemized quote that separates equipment, labor and the monitoring contract on three different lines.
Frequently asked questions
What is the average cost of a security system?
There isn’t one meaningful average, because a quote is really three prices bundled together: equipment, installation labor, and a monthly monitoring subscription. Published averages blur those and mislead. Ask each company to break the three apart on paper, state the contract length, and say plainly whether you own the equipment at the end or are leasing it.
What is the best security system without a monthly fee?
A self-monitored setup — sensors, a hub, a loud interior siren, and push alerts to your phone — is the no-fee route, and for many households it’s enough. The tradeoff is real: nobody calls police but you, and if you’re asleep or in a meeting, nobody calls at all. In the City of St. Louis, note that Ordinance 66264 requires registration for non-monitored systems too.
Does home insurance go down if you have a security system?
Usually a little. The Insurance Information Institute says you can generally get a discount of at least 5 percent for a smoke detector, burglar alarm or dead-bolt locks, and as much as 15 or 20 percent for a sophisticated sprinkler system plus a fire and burglar alarm that rings at police, fire or a monitoring station. Call your agent before you buy and ask what qualifies.
What are the downsides of home security systems?
Multi-year contracts you can’t easily exit, ongoing monthly cost, batteries and radios that need maintenance, and false alarms — which the Security Industry Alarm Coalition attributes roughly 85 percent of the time to user error. In the City of St. Louis, repeat false alarms can bring fees and eventually suspend police response to your address. Cameras add a privacy question about where footage is stored and who can view it.
Do you really need a security system?
Not everybody does, and the honest sequence is to fix the cheap layers first: solid deadbolts, exterior lighting, trimmed shrubs at entries, working smoke and carbon monoxide detectors. A system earns its keep when the house is empty for long stretches, when there’s a rear alley or basement entry you can’t see, or when a monitored fire and CO signal genuinely matters.
What security system do burglars hate?
Criminology surveys of convicted burglars keep landing on the same short list: noise, light, cameras aimed at the door they planned to use, and any sign somebody is home. Practically that means a loud interior siren, motion-triggered exterior lighting, a visible camera at the primary entry, and sensors on the back and basement doors rather than only the front.
What is the most highly rated home security system?
Ratings roundups disagree with each other because they weigh different things, and many are affiliate-funded. A better question locally is which company will still answer the phone in year three. Check the license — Illinois publishes Private Alarm Contractor licenses through IDFPR, and Missouri companies should hold the county or city license where you live — then ask for references on your side of the metro.
Do I need a permit for a home alarm in St. Louis?
Inside the city, yes. Ordinance 66264 requires registration of residential and commercial alarms, monitored or not, at $25 for a residential permit. If a company monitors your system it usually registers you rather than you paying the city. In St. Louis County and its municipalities, and across the Illinois side, rules differ — call the non-emergency line of the department that would respond.
What happens to my alarm if the internet or power goes out?
A properly installed panel has a backup battery and, in most current setups, a cellular communicator so it can still reach the central station when broadband or power drops. Systems that phone out only over your home internet go silent in an outage. Ask which communication path yours uses, ask how long the backup battery holds, and test it once a year with your monitoring company on the line.
Written by a dedicated team of St. Louis locals who live, work, and play right here in the St. Louis metro. Founder Lane Forman and team are committed to building the region’s most trusted directory by verifying listings and connecting local businesses with loyal customers across Missouri and Illinois.