The rule
From SDCI's Electrical Permit page (read 23 October 2026):
| Low-voltage job in a single-family house | Permit? |
|---|---|
| Security or burglar alarm | Yes: "security alarm systems... require an electrical permit" |
| Network, phone, TV, speaker wiring | No, under "Most low-voltage systems in single-family dwellings don't require a permit" |
| Thermostat or control wiring on its own | No, under the same line; new heating or cooling equipment has its own permit |
| Fire alarm system | SDCI lists the Fire Marshal for "alarms & sprinklers" as an agency to coordinate with |
| Any line-voltage work (a new outlet for the panel, a doorbell transformer on a new circuit) | Yes, a regular electrical permit |
SDCI's 2026 fee table backs this up in a footnote: "Single family dwelling electrical permits do not require additional fees for voice audio or data systems except for security systems, which require permit fees."
Who may pull it
"Any professional applying for electrical permits must have a Washington State electrical contractor's license and a Seattle business license. Property owners may do their own work when they own and occupy the property they're working on" (SDCI). An owner permit is for work you do yourself; if a company installs the alarm, its license number belongs on the permit. Check it on L&I Verify.
What it costs
From Table D-15 of SDCI's 2026 Fee Subtitle (effective 1 January 2026, read 23 October 2026):
| Item | 2026 fee |
|---|---|
| Low-voltage system (sound, security, fire alarm, nurse call, controls) | "Requires separate permit for each system" |
| Control unit | $17.52 each |
| Device (activating, horn, alarm, etc.) | $2.92 each |
| Communications systems (voice, data, coax, fiber): control unit / outlet | $17.52 / $2.92, maximum $636.56 |
| Minimum for a standard online (OTC) electrical permit | $105.12 |
| Administrative fee, every permit | $55.48 |
| Technology fee on all SDCI fees | 5% |
A house alarm with one panel and 15 sensors adds up to $17.52 + 15 × $2.92 = $61.32 in item fees, below the $105.12 minimum, so the permit is the minimum plus the $55.48 administrative fee, $160.60, and about $168.63 with the technology fee. Each system needs its own permit, so an alarm and a separate camera system are two.
How to apply and close it
- Apply online in the Seattle Services Portal: Permit – Trade, Construction, and Land Use, then the electrical permit. Without plan review, "You can print your permit the same day" (SDCI).
- Schedule the inspection online or on (206) 684-8900 before the permit expires. SDCI's electrical FAQ says you can get a two-hour window by calling your inspector between 7:00 and 8:00 a.m. on the day.
- Check the result on the portal record.
What 2,324 Seattle alarm and low-voltage permits show
| Measure | Seattle alarm and low-voltage |
|---|---|
| Permits on homes, October 2023 to September 2026 | 2,324 |
| Firms | 169 |
| Firms with a permit in the last 12 months | 88 |
| Firms with one permit only | 103 (60.9%) |
| Busiest firm's share | 39.7% |
| Five busiest firms' share | 75.1% |
| Usual filed value | $1,200 |
| Middle half of firms' usual value (39 firms) | $1,500 to $12,500 |
| Completed (permits a year or more old) | 95.2% |
| Usual days from issue to completion | 23 |
| Firms matched to an active L&I record | 85.8% |
| Busiest / quietest month | May (index 116) / August (81) |
This is a two-firm market with a long tail. The busiest firm, ADT LLC, filed 39.7% of all permits, the five busiest 75.1%, and 60.9% of firms filed just one. The value range is wide, $1,500 to $12,500 for the middle half of firms, because the trade mixes a basic alarm with whole-house control and wiring jobs filed by electricians and heating companies. Almost everything gets completed (95.2%), so an alarm installer with expired permits stands out. 12 firms matched an L&I record that is no longer active.
See every Seattle alarm and low-voltage installer by permits completed →
Related
Line-voltage work: Seattle electrical permit. Choosing the installer: hiring an electrician in Seattle. Checks: Seattle contractor license lookup, Seattle building permit search. Rules elsewhere: do I need a permit for electrical work. Counts by year and month: Seattle permit statistics.
What this does not tell you
Our alarm and low-voltage trade is the permits SDCI files under that heading; exempt network and speaker wiring leaves no record, so it is not here. The filed value is the applicant's estimate. Owner permits name no firm. License status is our name match to L&I's file.
How we know this
The permit rule and licensing rule are quoted from SDCI's Electrical Permit page, fees and the voice/audio/data footnote from Table D-15 of SDCI's 2026 Fee Subtitle, and the inspection window from SDCI's electrical FAQ, all read 23 October 2026. Counts are SDCI alarm and low-voltage permits on Seattle homes, October 2023 to September 2026; "completed" uses permits a year or more old. License status is our name match to Washington L&I.
Numbers come from City of Seattle (SDCI) building, trade and electrical permits on single-family and duplex homes (the city's open-data exports), data through October 17, 2026. Nobody paid to be on this page and nobody can.
Questions
- Do I need a permit for a security system in Seattle?
Yes. SDCI says most low-voltage systems in single-family homes don't need a permit, 'except security alarm systems, which require an electrical permit'. The alarm company normally pulls it.
- Do I need a permit for network, TV or speaker wiring in Seattle?
Not in a single-family house. SDCI exempts most low-voltage systems in single-family dwellings, and its fee table says single-family electrical permits need no additional fees for voice, audio or data systems, security systems excepted.
- How much is a low-voltage permit in Seattle?
Under SDCI's 2026 Fee Subtitle, a low-voltage system is $17.52 per control unit and $2.92 per device, but a standard online electrical permit has a $105.12 minimum plus a $55.48 administrative fee, and a 5% technology fee applies. A house alarm usually pays the minimum, about $168 in all.
- Who can pull a security alarm permit in Seattle?
A professional needs a Washington State electrical contractor's license and a Seattle business license. An owner who lives in the house may pull a permit for work they do themselves.
- How long does an alarm permit take to close in Seattle?
The usual Seattle alarm and low-voltage permit in our file was completed 23 days after issue, and 95.2% of those a year or more old were completed.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Do I need a permit? 13 common home projects, checked against city rules and permit files
- Do I need a permit for an electrical panel upgrade? Yes: the rule in 13 cities, and how long it takes
- Do I need a permit to install an EV charger? Yes for Level 2: the rule in 9 cities
- Do I need a permit for electrical work? The rule in 13 cities, and how many get filed
For one city
- Electrical Permit — Seattle Department of Construction and Inspections (accessed 2026-10-23)
- 2026 Fee Subtitle (SMC 22.900), Table D-15 Electrical Permit Fees — SDCI (accessed 2026-10-23)
- Electrical Permits & Inspections FAQ — SDCI (accessed 2026-10-23)
- Seattle Services Portal — City of Seattle (2026-10-23)
- Verify a Contractor, Tradesperson or Business — Washington L&I (2026-10-22)