What does NAICS stand for?

North American Industry Classification System. It's a six-digit code system the U.S., Canada, and Mexico use to classify what a business actually does.

Do I have to use a NAICS code for my small business?

In practice, yes. You'll be asked for one on your EIN application, most state LLC filings, Schedule C of your federal tax return, business licenses, and SBA loan or size-standard paperwork.

Can I change my NAICS code later?

Yes. It's not permanent. If your business activity shifts, you update the code on your next relevant filing — it doesn't require reopening your LLC or EIN.

What Is a NAICS Code?

Short answer, then the real answer — and where this six-digit number is actually going to show up in your business.

The short answer

A NAICS code is a six-digit number that tells the government what your business does for a living. NAICS stands for North American Industry Classification System — it's used across the United States, Canada, and Mexico so that a business can be sorted into a category consistently, no matter which agency is asking.

If you drive for a delivery app, sell hand-poured candles online, do freelance graphic design, or run a woodworking shop out of your garage, there's a code that matches that activity. You don't invent the number — you look it up and use the one that fits what you actually do to bring in money.

Why this exists in the first place

NAICS was built jointly by statistical agencies in the U.S., Canada, and Mexico and adopted in 1997, replacing an older system called SIC (Standard Industrial Classification). The goal wasn't to make paperwork harder — it was to let three countries compare economic data using the same categories, and to let U.S. agencies like the IRS, SBA, and state licensing boards sort millions of businesses into groups that actually mean something.

Every code gets updated on a five-year cycle so new industries — app-based gig work, e-commerce, digital services — get their own category instead of getting crammed into something that doesn't fit. The version in use now is NAICS 2022.

How the six digits actually break down

The code isn't random. Each digit narrows the category further:

First two digits — the broad sector (for example, 45 is Retail Trade)
Third digit — subsector
Fourth digit — industry group
Fifth digit — NAICS industry
Sixth digit — the most specific classification, often country-specific to the U.S.

So a code like 454110 (Electronic Shopping and Mail-Order Houses) tells you, reading left to right, that it's Retail Trade → a specific subsector → narrowing all the way down to online-only retail. You don't need to memorize this structure to use it — you just need to know that more digits means more specific, and specific is what most forms actually want.

Practical takeaway: When a form asks for "your NAICS code," it wants the full six digits, not just the two-digit sector. Search by keyword instead of trying to reverse-engineer the numbering.

Where you'll actually be asked for one

This isn't a number you file away and never see again. It shows up on:

Your EIN application (Form SS-4) — the IRS asks what your business does
State LLC or business registration paperwork — most states require it at formation
Schedule C of your Form 1040 — if you're a sole proprietor or single-member LLC filing taxes, there's a dedicated NAICS box
Business licenses and permits — many cities and counties tie licensing categories to it
SBA loan applications and size-standard eligibility — whether you qualify as a "small business" for federal programs is often decided by revenue or employee thresholds tied to your specific code
Business insurance applications — insurers use it to price risk

This is true whether you're driving for a rideshare app between shifts, launching your first LLC at 23, or starting a consulting business after retiring from a 30-year career. The form doesn't care how long you've been in business — it just wants the code.

Common mix-ups worth clearing up

"I'm too small to need one." Size doesn't exempt you. A single-person operation with no employees still gets asked for a NAICS code the first time it touches an EIN application or a Schedule C.

"I have to pick the perfect code or I'm locked in forever." You're not. Businesses shift what they do all the time, and the code isn't a life sentence — it's updated on your next relevant filing if your primary activity changes.

"I do five different things, so I need five codes." You pick the one that matches your primary revenue-generating activity — the thing that brings in the most money, not everything you're capable of doing.

What to do next

Now that you know what the number means and who's actually reading it, the next step is finding the specific code that matches your business:

Already know roughly what you do for income? Search by keyword using the tool below.
Setting up a single-member LLC and want a walk-through on choosing between two close codes? See How to Choose the Right NAICS Code for a Single-Member LLC.
Doing rideshare, delivery, or freelance work? Start with Top NAICS Codes for Gig Workers and Independent Contractors for the most commonly searched codes.

Search NAICS Codes →