Naics 561621 Industry Statistics Data: Dataset Structure and Field Coverage

NAICS 561621 covers Security Systems Services - except Locksmiths: the firms that install, service and monitor burglar and fire alarms, access control and CCTV systems across the United States. It is a six-digit code inside subsector 5616 (Investigation and Security Services), which matters when you pull data because some federal tables publish only at the five-digit 56162 line rather than the six-digit one.

Two more federal sources extend the picture beyond headcounts. IRS Statistics of Income aggregates Schedule C filings into NAICS-level receipts, deductions and net income, giving a tax-based revenue read that no Census product offers at annual frequency. The SBA Small Business Profiles put state-by-state small-business context around those national totals.

The backbone is County Business Patterns, published annually through api.census.gov back to 1986. Filter any CBP call to NAICS2017=561621 and you get establishment counts (ESTAB), employment (EMP) and first-quarter plus annual payroll (PAYANN) broken out by county, state, metropolitan area, place and ZIP Code Business Patterns geography, with employment-size-class splits on top.

IRS Statistics of Income - Nonfarm Sole Proprietorships is the only slice source reporting actual dollar receipts for the trade at national level. Drawn from Schedule C of Form 1040, its four tables cover business receipts, selected deductions, total deductions, payroll and net income by NAICS industry: Table 1 classifies by sector, Table 2 gives the full income statement, Table 3 cross-tabulates returns and receipts by size-of-receipts class, and Table 4 adds income items by AGI class, marital status and age.

One caveat belongs in every methodology note: because sole proprietorship is the dominant legal form among small alarm-installation firms, the SOI rows give a tax-based read on revenue and profitability that complements Census counts rather than duplicating them. A dealer who incorporates drops out of Schedule C and reappears only in the Census employer tables, so the two sources bracket the market from opposite ends.

For the employer side of that bracket, SBA Small Business Profiles publishes firm counts, employment and openings/closings as 58 PDF profiles per edition covering all 50 states, DC, the territories and the nation - the fastest read on state-level market entry.

Establishment counts tell you how many sellers exist; burglary exposure tells you why anyone buys. Three free datasets carry that demand side.

The FBI Crime Data Explorer serves NIBRS and Summary Reporting offense counts for every US state, county and agency through a JSON REST integration keyed with a free api.data.gov registration, with SRS series reaching back to the 1960s and NIBRS participation expanding from 1991. Bulk CSV archives sit alongside the API.

The National Crime Victimization Survey captures what police records miss: roughly 240,000 people in about 150,000 households interviewed annually since 1973, including burglaries never reported to police. Collection spans 1973-2024, with person- and household-level microdata archived at ICPSR/NACJD series 95.

Joining these to the Census counts turns 'how many installers operate in this county' into 'how many installers does this much measured burglary support.'

Six sources cover the NAICS 561621 question set without overlap. The comparison turns on grain: only the Census programs go below state level, and only IRS SOI reports dollars of receipts at annual frequency.