Industry classification without scraping Census.
NAICS 2022 across all 20 sectors down to 6-digit national industries, ranked keyword search for "what code is this business?", and a SIC→NAICS crosswalk for legacy data — the three operations onboarding, KYB and underwriting forms actually need, behind one API key.
curl -H "Authorization: Bearer YOUR_API_KEY" \
"https://almanac.tools/v1/naics/lookup?code=541511"{
"data": {
"code": "541511",
"title": "Custom Computer Programming Services",
"level": "national",
"parent": "54151",
"sic": ["7371"]
}
}- 20
- NAICS 2022 sectors (incl. ranged 31-33, 44-45, 48-49)
- 226
- Codes from sector to 6-digit national industry
- 59
- SIC-crosswalked national industries
- 2022
- NAICS vintage (current U.S. edition)
The NAICS Industry Codes API resolves a NAICS 2022 code to its official title and hierarchy, ranks free-text industry descriptions to candidate codes, and crosswalks legacy 1987 SIC codes to their NAICS equivalents. It covers all 20 sectors down to 6-digit national industries, so onboarding, KYB and firmographic-enrichment forms can classify a business without scraping the Census site.
Built for the awkward middle.
Lookup, search and crosswalk in one place
A code lookup returns the official title, level (sector → national) and parent. A keyword search ranks free-text descriptions to candidate codes. A SIC crosswalk maps legacy 1987 SIC codes forward to NAICS — three endpoints that together cover the whole classification job.
Built for onboarding and KYB forms
When a customer types "custom software" or picks "541511", you need the canonical title, the sector it rolls up to, and its parent chain. The API returns all of it, including the ranged sectors (31-33 Manufacturing, 44-45 Retail, 48-49 Transportation) that trip up naive 2-digit parsers.
SIC→NAICS without the lookup tables
Legacy CRMs, bureau data and old filings still carry 1987 SIC codes. GET /v1/naics/crosswalk?sic=7371 returns every NAICS entry that maps from that SIC, so you can migrate firmographic data forward instead of maintaining your own crosswalk spreadsheet.
Endpoints
Every route takes a Bearer API key. Validation runs before authentication, so a malformed request never costs you a credit.
| GET | /v1/naics/lookup | Resolve a NAICS code (2–6 digit or ranged sector) to its title, level and parent. |
| GET | /v1/naics/search | Ranked keyword search over industry titles. Query: q, optional limit. |
| GET | /v1/naics/sectors | List all 20 NAICS 2022 sectors. |
| GET | /v1/naics/crosswalk | Map a 1987 SIC code to its NAICS 2022 entries. Query: sic. |
Frequently asked
What is the difference between NAICS and SIC?
SIC (Standard Industrial Classification, last revised 1987) is the legacy U.S. system; NAICS (North American Industry Classification System) replaced it in 1997 and is now the standard. NAICS is hierarchical — 2-digit sector, 3-digit subsector, 4-digit industry group, 5-digit industry, 6-digit national industry. Lots of legacy data still carries SIC, which is why this API includes a SIC→NAICS crosswalk.
Which NAICS vintage do you use — 2022 or 2017?
NAICS 2022, the current U.S. edition. It reflects the 2022 restructuring (for example sector 51 Information was reorganized and the old code 518210 became "Computing Infrastructure Providers, Data Processing, Web Hosting, and Related Services"). If you have a 2017-coded dataset, most 6-digit codes are unchanged, but treat any code in a restructured sector with care.
Why are some sectors a range like 31-33 instead of a single number?
Three NAICS sectors span multiple 2-digit prefixes: Manufacturing is 31-33, Retail Trade is 44-45, and Transportation and Warehousing is 48-49. The API returns the canonical range string as the sector code, and a lookup on any member prefix (31, 32 or 33) resolves to "31-33". This is the detail naive 2-digit parsers get wrong.
How does keyword search rank results?
GET /v1/naics/search does a case-insensitive match over official titles and ranks best-to-worst: a whole-word match, then a word-prefix match, then a plain substring match. Ties break toward shallower (shorter) codes first, so "software" surfaces the Software Publishers industry group before deeper leaves. Pass limit to cap the result count (default 25).
How complete is the SIC crosswalk?
Honestly: the crosswalk is attached to 59 well-known 6-digit national industries, not the full SIC table. It covers the common cases you hit in KYB and firmographic data (banking, software, restaurants, contractors, retail, healthcare), and a SIC with no mapping returns an empty result rather than a guess. If you need a SIC we do not yet map, tell us — adding a crosswalk row is trivial.
Does this include every NAICS code?
Not yet. This is a strong, representative set — 226 codes spanning all 20 sectors from 2-digit down to 6-digit national industries, weighted toward the industries that show up in onboarding and underwriting. It is not the full ~1,000-code 6-digit table. The data model is the official one, so deepening coverage is additive: request the codes you need and we extend.
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Start building with NAICS Industry Codes.
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