To build a business list by industry, do three things in order: translate the industry into standard codes (SIC and NAICS), size the market with free Census data, then pull the actual businesses from registries, associations, directories, or a database that filters by code and exports contacts. That first step is the one everyone skips. Labels lie; codes don’t. And I’ll show you real code-level numbers below that you won’t find anywhere else.
I’m going to be honest with you: I skipped that first step for years. It cost me.
In 2021, I built a “plumbing companies” list for a water-tech client in Munich by filtering on the label “contractor”. The kickoff call was rough. Their sales lead read out the first ten rows: two general contractors, a roofer, and a kitchen remodeler. Not one plumber. We re-pulled the list by actual plumbing codes and the campaign recovered, but I’ve never trusted a label since.
Here’s the source landscape at a glance, then the full system.
| Source | Filters by | What you get | Cost |
|---|---|---|---|
| Census County Business Patterns | NAICS code, geography | Establishment counts, no names | Free |
| State registries and licensing boards | License type, profession | Official rosters of licensed businesses | Free |
| Industry associations | Membership | Small, warm member directories | Free to cheap |
| Directories and review sites | Category | Names, some phones, reviews | Free |
| LinkedIn and sales tools | Self-reported industry | Companies with an online presence | Free-ish |
| Business database with code filters | SIC, NAICS, geography, quality | Exportable records with contacts | Free tier, then paid |
Why “Industry” Is Trickier Than It Looks
“Restaurant” is a label. NAICS 722511 is a definition. That difference decides whether your list contains what you think it contains.
Here’s the thing. Every platform slices industries differently. Google Maps has its own categories. LinkedIn lets companies pick their own industry, and they choose generously. Directories invent whatever taxonomy suits them. Only two systems are standardized across the whole US economy: SIC codes (the old standard) and NAICS codes (the current one). They’re the backbone of firmographic data, and they’re the reason my Munich list failed: I filtered on a loose label when a precise code existed.
Want to see the mess in one example? Take a med spa. On Google Maps it might sit under “medical spa”, “skin care clinic”, or “beauty salon”, depending on what the owner picked. On LinkedIn it probably calls itself “Health, Wellness and Fitness”. A directory files it under “Spas”. And in the code systems it has an actual defined home, with a written definition you can read and test against.
One business. Four different answers to “what industry is this?”. Build a list of businesses by industry on the first three and you inherit somebody’s guess. Build it on codes and you inherit a definition.
So every serious business list by industry starts with the same move. Find your codes first.
Step 1: Turn Your Target Industry Into Codes
Three lookups get you there, and they’re all free:
- Search your industry keyword on the NAICS.com lookup tool and note every code that matches what your targets actually do
- Confirm definitions on the official Census NAICS page, which includes the full written description for each code
- Find the four-digit SIC ancestor in the OSHA SIC manual, because plenty of tools and vendors still key on SIC
My habit: I read the full written definition before I filter on any code. Every time. The definition tells you what’s included AND what’s excluded, and the exclusions are where lists go wrong.
Here’s a real exclusion that surprises people. NAICS 721110 is “Hotels (except Casino Hotels) and Motels”. See that parenthesis? Casino hotels live in their own code, 721120. So a “hotels” list built on 721110 alone quietly drops every casino resort in Nevada. Nothing was broken. The definition simply said “except”, and nobody read it.
To make this concrete, here are ten familiar verticals with both codes, plus the number of US records carrying each code in the CUFinder database as of September 2026:
| Business type | SIC code | US records (SIC) | NAICS code | US records (NAICS) |
|---|---|---|---|---|
| Restaurants | 5812 | 1,079,384 | 722511 (full-service) | 650,371 |
| Real estate | 6531 | 399,136 | 531210 | 297,697 |
| Beauty salons | 7231 | 449,784 | 812112 | 307,259 |
| Grocery stores | 5411 | 428,282 | 445110 | 238,052 |
| Dentists | 8021 | 264,649 | 621210 | 273,118 |
| Law offices | 8111 | 228,882 | 541110 | 229,041 |
| Hotels | 7011 | 223,454 | 721110 | 117,320 |
| Insurance agents | 6411 | 181,987 | 524210 | 174,811 |
| Gyms and fitness | 7991 | 173,576 | 713940 | 245,004 |
| Plumbers | 1711 | 144,383 | 238220 | 159,101 |
Same business type, different counts: SIC records vs NAICS records
Source: CUFinder Local Business Database, 210M+ records, September 2026.
Source: CUFinder local business database, September 2026.
Notice the counts rarely match between systems. That’s not an error. The two systems draw their category borders in different places, which is exactly why you check both.
💡 Pro Tip: Search NAICS.com with what the business DOES, not what it's called. "Installs pipes" finds plumbing codes. "Contractor" finds forty codes you don't want. Verbs beat nouns in code lookups.
Step 2: Decide Between SIC and NAICS (or Use Both)
The short answer: NAICS for government data and modern targeting, SIC for SEC filings, insurance, and legacy vendor files. Both when your tool allows it, because vendors differ in which system they index best. I keep a full comparison of SIC vs NAICS for business lists if you want the complete breakdown.
But here’s the one difference that changes list building the most: granularity.
SIC lumps. NAICS splits. Take restaurants. SIC 5812 “Eating Places” holds 1,079,384 US records in our data. One bucket, everything from white tablecloths to taco trucks. NAICS breaks that same world into full-service restaurants (722511: 650,371 records), limited-service restaurants (722513: 304,555), and snack and beverage bars (722515: 104,214), among others. Same businesses, different resolution. And the split is not cosmetic: the two restaurant codes even behave differently online. In our September 2026 US data, 57.6% of limited-service restaurants link an Instagram profile versus 27.5% of full-service ones, because fast-casual chains run central social accounts.
Why does that matter? Because in 2023 I ran a campaign for a POS vendor in Austin whose product only made sense for sit-down service. The first list used the SIC-style “restaurants” bucket. Replies were meh. We re-cut it to full-service codes only, rewrote one line of the email to match, and replies climbed. Precision in, precision out.
One more wrinkle before you commit: NAICS has vintages. The system revises every five years, and the 2022 revision restructured retail heavily. Pharmacies, for example, moved from 446110 in the 2017 vintage to 456110 in 2022. Real-world data reflects the mess: our own database still carries 119,701 US records under 445120, the 2017-era convenience store code, alongside 2022-vintage codes. Any large dataset you touch will mix vintages, so note which one your source speaks before you filter.
Step 3: Pull the List From the Right Source
Codes chosen. Now the actual list. Six sources, free ones first, with honest limits for each.
Census County Business Patterns (Free Counts)
County Business Patterns tells you how many employer establishments exist for any NAICS code, in any county, metro, or state. Search the table on data.census.gov, filter to your code and geography, and you have official market sizing in minutes. Its ZIP-level cousin does the same per ZIP, and I’ve written a full walkthrough of building a list of businesses by ZIP code that pairs beautifully with this one.
Limits: counts only, employer businesses only, and about a two-year lag. Use it to size territories and set quotas, not to find names.
The sizing math is worth the ten minutes every single time:
→ Code: your NAICS target → CBP count: how many exist in the territory → Reality check: can your team even work that many, or do you need three more counties?
State Registries and Licensing Boards (Free Names)
Here’s the underrated one. Secretary of State registries are weak for industry searches (they index legal names, not activities). But LICENSED industries have public rosters, and those rosters are gold. Contractor license boards list every licensed contractor by classification. Health boards list clinics and practitioners. Bar associations list law firms. Insurance departments list agencies.
If your target industry needs a license to operate, someone official keeps a list of everyone in it. Search “[state] [profession] license lookup” and you’ll usually find a searchable, sometimes downloadable roster. California’s contractor board, for instance, lets you search licensees by classification, so “C-36” hands you the state’s licensed plumbers. Texas does the same for HVAC. Most states mirror this for electricians, cosmetologists, pharmacists, and dozens more trades.
Limits: format chaos from state to state, no emails, and mailing addresses that point to registered agents instead of shops. Still, for licensed trades this is the most complete free roster that exists, and it’s refreshed by law.
Industry Associations (Small but Warm)
Trade associations publish member directories: home builders, independent pharmacies, craft brewers, you name it. The lists are small, but membership signals an engaged, established business. I like association lists as a seed layer for high-touch outreach, then I broaden with bigger sources.
And a bonus you only notice after a few campaigns: association members answer email at a higher rate than cold directory pulls, because they’re the joiners of their industry. Limits: members only, often gated, and rarely more than a name, city, and website.
Directories and Review Sites (Category Roulette)
Yelp, Yellow Pages, and friends organize businesses by their own categories. Fine for a quick 40-name list in one metro. The pain: their categories don’t map cleanly to codes. Yelp’s “Contractors” is my Munich mistake wearing a different hat. So if you collect from directories, tag each record with your own code as you go, or you’ll inherit their fuzziness. For the wider free toolkit beyond industry filters, my guide to getting a list of businesses in your area covers directories, chambers, and more.
LinkedIn and Sales Tools (Thin for Local)
LinkedIn lets you filter companies by industry, and B2B sales tools inherit that field. Two catches for local lists. First, the industry field is self-reported, so a landscaping company can call itself “Environmental Services”. Second, coverage: only about 30% of the US local business records in our database carry a LinkedIn URL at all. Main-street businesses live on Maps and Instagram, not LinkedIn. Use it for people data on bigger targets, not as your primary industry filter.
A Business Database With Code Filters (Contact-Ready)
This is the route built for exactly this job. The workflow: enter your SIC or NAICS code, stack geography on top (country, state, city, ZIP), add quality filters like minimum rating or “has email”, then export to CSV or push to your CRM. If you’re comparing tools, start with how to choose a local business database, and check which code systems each one actually supports, because many skip codes entirely. I’ve also reviewed the best local business databases side by side.
Where does CUFinder sit in this? You can search local businesses by SIC or NAICS code directly, across 200M+ local businesses in 6,000+ industries, with 11 stackable filters. Every record carries both code systems plus emails, phones, and social profiles where available. In practice the pull looks like this:
- Enter your industry, SIC code, or NAICS code in the category filters
- Stack the geography: country, state, city, or postal code
- Add quality filters, like rating 4+ or “has email”, to match your outreach channel
- Save the matching businesses to a named list you can refine later
- Export to Excel or push straight to your CRM
And the honest limitation: codes on any large database, ours included, are assigned at scale by automated classification, and edge cases get misfiled. A food truck can land in a restaurant code, a med spa in a salon code. So run my standing sample check: pull 50 records for your code, eyeball all 50, and count how many are truly your target. Two minutes. It would have saved my Munich kickoff call.
What the Codes Look Like in a Live Database
Nobody publishes this, so here’s what industry codes actually look like across a big places database. As of September 2026, live records in the CUFinder database carry 774 distinct four-digit SIC values and 876 distinct six-digit NAICS values. Validated against the official code lists, that’s 689 official 1987 SIC codes and 797 official NAICS codes in active use. And coverage is essentially total in the US: 18,400,257 of 18,400,261 US records carry a SIC code, and effectively all carry a NAICS code.
Why don’t all 1,000-plus official codes show up? Because a local business database skews toward businesses with a door and a map pin. Restaurants, clinics, salons, repair shops. The missing codes cluster in niche manufacturing and wholesale subsectors, the kind of businesses that live in industrial parks and trade registries rather than on Google Maps. Useful to know: if your target is “injection molding plants”, a places-first database is the wrong first stop, and a registry or trade directory is the right one. Match the source to the industry’s habitat.
So which codes dominate the storefront world? Here are the top US SIC codes by record count:
| SIC | Official title | US records |
|---|---|---|
| 5812 | Eating Places | 1,079,384 |
| 8011 | Offices and Clinics of Doctors of Medicine | 761,068 |
| 7999 | Amusement and Recreation Services, NEC | 632,790 |
| 8661 | Religious Organizations | 564,635 |
| 7231 | Beauty Shops | 449,784 |
| 8049 | Offices and Clinics of Health Practitioners, NEC | 432,007 |
| 5411 | Grocery Stores | 428,282 |
| 6531 | Real Estate Agents and Managers | 399,136 |
The biggest SIC codes in the US by business records
Source: CUFinder Local Business Database, 210M+ records, September 2026.
Source: CUFinder local business database, September 2026.
One honest note about that table. A places database indexes every mapped establishment, so a few high-ranking codes (churches, recreation spots, community places) are not storefront businesses. That’s what “local business data” really contains, and a good filter strategy embraces it: you exclude what you don’t sell to. For the bigger picture across countries and industries, my local business statistics roundup runs the full numbers.
Here’s the part that actually changes campaign plans: reachability differs by code as much as headcount does. Same top codes, same query, contact fields added:
| SIC | US records | Has website | Has email | Has Instagram |
|---|---|---|---|---|
| 5812 Eating Places | 1,079,384 | 66.5% | 28.0% | 38.6% |
| 8011 Offices of Doctors of Medicine | 761,068 | 51.9% | 30.9% | 27.9% |
| 7999 Amusement & Recreation, NEC | 632,790 | 35.9% | 22.2% | 17.2% |
| 8661 Religious Organizations | 564,635 | 47.6% | 29.4% | 13.1% |
| 7231 Beauty Shops | 449,784 | 51.0% | 18.0% | 22.0% |
| 8049 Health Practitioners, NEC | 432,007 | 45.0% | 26.6% | 18.8% |
| 5411 Grocery Stores | 428,282 | 52.2% | 13.6% | 37.8% |
| 6531 Real Estate Agents & Managers | 399,136 | 71.7% | 43.4% | 22.5% |
Source: CUFinder local business database, US records, September 2026. Shares are approximate.
Read the email column top to bottom. Real estate offices (43.4%) are emailable at more than three times the rate of grocery stores (13.6%), and beauty shops sit near the bottom at 18.0%. The code you pick decides your channel, not just your audience: an email-first campaign into SIC 5411 starves, while the same budget into 6531 has a real denominator. Toll-free lines tell a second story: 2.4% of real estate offices route through one, versus 0.8% of restaurants, a small but reliable chain-and-franchise tell when you want independents only.
📌 Example: Dentists are the clean case: SIC 8021 maps to NAICS 621210, one to one, and both hold about 270,000 US records in our data. When your vertical maps that cleanly, either code works. Most don't map that cleanly.
The Crosswalk Problem (SIC to NAICS Is Not One-to-One)
Sooner or later, a vendor sends you a SIC-coded file while your targeting lives in NAICS, or the reverse. Translation between the systems is a real task with real traps. First, what NAICS is, straight from the source:
“The North American Industry Classification System (NAICS) is the standard used by Federal statistical agencies in classifying business establishments for the purpose of collecting, analyzing, and publishing statistical data related to the U.S. business economy.”
U.S. Census Bureau, census.gov/naics
The old system it replaced never left, though, and the two don’t align neatly. The Census Bureau publishes official concordance tables that map 1987 SIC codes to NAICS. Working through that concordance, the 1987 manual holds just over 1,000 four-digit codes, and 453 of them map to MORE than one NAICS code. The record holder is SIC 7389, “Business Services, NEC”, which fans out into 42 different NAICS codes. Forty-two!
I learned this the slow way. A list vendor once sent me an SIC-coded file, I translated it with a quick one-to-one lookup, and half my NAICS targets vanished in the process. Two days of cleanup. So here’s the process that works:
- Define your targets in NAICS first, since it’s current and more precise
- When a source is SIC-only, look up each SIC code in the Census concordance
- Review EVERY candidate NAICS code it maps to, and keep only the ones matching your written definition
- Store both codes as separate columns in every export, forever
That last rule is non-negotiable for me now. Storage is free. Re-translating a 40,000-row list is not.
Going the other direction, NAICS to SIC, is gentler but not clean either. A precise six-digit NAICS target often rolls up into a broader SIC code that drags neighbors along with it. So when a vendor can only take SIC, send the SIC code AND your written definition of who you actually want. The definition survives translation. The code alone doesn’t.
🔍 Did You Know? SIC 7389 "Business Services, NEC" became a catch-all for everything the 1987 manual couldn't foresee. That single code crosswalks to 42 NAICS codes, from interior design to telemarketing bureaus. If your vendor list leans on 7389, expect a zoo.
Common Mistakes to Avoid
Five mistakes cover most bad industry lists:
- Filtering by label only. “Contractor”, “consultant”, and “agency” are vibes, not definitions. Codes first, always.
- Assuming one code covers the vertical. Restaurants span at least three NAICS codes. Check the neighbors of your code before you export.
- Mixing NAICS vintages. NAICS 2022 restructured retail codes heavily. A 2017-coded file and a 2022-coded file disagree about the same store, so ask your source which vintage it uses.
- Trusting SIC alone for modern industries. The 1987 manual predates the public internet. App developers, med spas, and solar installers get squeezed into catch-all codes there.
- Skipping verification. Whatever the source, sample 50 records and verify emails before outreach. Codes tell you the industry, not whether the inbox is alive.
🧠 Fun Fact: The 1987 SIC manual has no code for software publishing as we know it, because the modern software industry barely existed when the manual froze. NAICS fixed that in 1997, and it keeps revising every five years.
FAQ: Building a Business List by Industry
How do I get a list of businesses by industry?
Translate the industry into SIC and NAICS codes, then pull from sources that support them. Census data gives free counts, licensing boards give official rosters, and business databases give exportable records with contacts. Filtering by code instead of label is what keeps the list clean.
Can I get a list of companies by NAICS code?
Yes. For counts, filter County Business Patterns tables by your NAICS code for free. For actual company records, use a business database that supports NAICS filters, enter the six-digit code, add your geography, and export. Sample the results first, since automated code assignments include some misfiles.
How do I find a company’s SIC or NAICS code?
Look the company up in a code lookup tool like NAICS.com, or check a business database record. Databases usually list both codes per company, and public companies carry an SIC code on their SEC filings. For your own business, pick the code whose official definition matches your primary activity.
How many NAICS codes are there?
NAICS 2022 defines 1,012 six-digit industries, organized under 20 sectors. In practice, not all appear equally: our database shows 797 official NAICS codes carrying live US and international business records as of September 2026. The system revises every five years, so counts shift slightly per vintage.
Are SIC codes still used?
Yes, heavily. The SEC still assigns SIC codes on filings, insurance underwriting leans on them, and many older business data products index by SIC. The system hasn’t been updated since 1987, but it refuses to retire, which is why smart lists carry both codes.
Which industry has the most businesses in the US?
Restaurants lead among storefront codes: SIC 5812 “Eating Places” tops our US table with about 1.08 million records. Medical offices, beauty shops, and grocery stores follow. Community places like religious organizations also rank high, since a places database indexes every mapped establishment.
Is there a free list of businesses by industry?
Free gets you counts and partial rosters. Census County Business Patterns provides free counts by NAICS code and geography, and licensing boards publish free rosters for licensed trades. Full contact-ready lists of businesses by industry come from databases, which cost money, or directory collection, which costs time.
Should I filter by industry label or by code?
Use labels to explore and codes to commit. Labels help you discover how an industry describes itself, but they overlap and mislead. Codes have written definitions and stable borders. My rule: browse by label, build by code, and keep both SIC and NAICS on every record.
It’s Time to Build Your Industry List
Pick one target industry and find its codes tonight. That’s it. That’s the assignment.
→ Look up the codes → read the definitions → size it with CBP → pull from two sources → sample 50 → launch
The whole difference between my Munich disaster and my Austin win was that first step. Same me, same tools, one new habit. Your business list by industry gets sharper the moment you trade labels for codes, and everything downstream (targeting, copy, replies) sharpens with it.
You’ve got this. Which industry are you building for? Tell me in the comments, and if you’ve found a licensing-board roster that saved you, share it. Those tips are gold.
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