How many NAICS codes can I have?

You have one primary NAICS code and can add as many additional codes as legitimately describe your business. There's no benefit to padding the list — focus on codes for work you can actually perform, since the right additional codes broaden the opportunities you match without misrepresenting your company.

How do NAICS codes affect whether I'm a small business?

The SBA assigns a size standard to each NAICS code, set as either a maximum number of employees or maximum average annual revenue. Whether you qualify as small depends on the code attached to a specific contract, so you can be considered small under one code and not under another.

Can I change my NAICS codes after I register?

Yes. NAICS codes aren't permanent — you can update them in your registration as your business grows or shifts into new lines of work. It's good practice to review them periodically so you keep surfacing for the opportunities that fit you.

What's the difference between my primary and additional NAICS codes?

Your primary code is the single one that best represents your core line of business, while additional codes cover the other things you do. The primary code acts as your headline classification, and additional codes expand the range of opportunities and set-asides you can match and compete for.

Where do NAICS codes come from?

NAICS is the North American Industry Classification System, a standardized way the U.S., Canada, and Mexico classify businesses by industry. Each code is six digits, and the federal government uses these codes to tag both contract opportunities and the businesses registered to compete for them.

NAICS Codes for Government Contracting: How to Choose Yours

If you're getting set up to sell to the federal government, few things shape your results as quietly — or as powerfully — as your NAICS codes. These short numeric codes decide which contract opportunities you show up for, and they're also the yardstick the government uses to decide whether your business counts as "small." Choose well and the right work finds you. Choose poorly and you're either invisible to buyers or stuck competing against companies many times your size.

This guide explains what NAICS codes actually are, how they drive opportunity matching and SBA size standards, how to find and choose the right ones, and the difference between your primary and additional codes — all in plain English for a busy small-business owner.

What is a NAICS code?

NAICS stands for the North American Industry Classification System. It's the standard system the U.S., Canada, and Mexico use to classify businesses by what they do. Each code is six digits, and the digits get more specific as you read left to right — the first two describe a broad sector, and the full six pin down a particular industry. For example, a sector like construction narrows down to a specific trade or service the further out you go.

In federal contracting, NAICS codes are how the government tags both your business and the work it buys. When a contracting officer posts an opportunity, they assign it a NAICS code that best describes the work. When you register your business, you list the codes that describe what you offer. That shared language is what makes matching possible.

How NAICS codes drive opportunity matching

Because every solicitation carries a NAICS code, those codes are one of the main filters buyers and vendors use to find each other. If your registration doesn't list a code, you generally won't surface for opportunities tagged with it. Get your codes right and relevant work becomes far easier to find — you can search live federal opportunities by keyword, NAICS code, and set-aside to see exactly what's out there for your industry.

Discovery — buyers and search tools filter opportunities by NAICS, so missing codes mean missed matches.
Eligibility — many set-aside opportunities are scoped to a specific NAICS code and its size standard.
Positioning — your codes signal to contracting officers what your company actually does.
Reporting — the government tracks small-business goals by NAICS, which influences who agencies seek out.

NAICS codes and SBA small-business size standards

Here's the part many owners miss: there is no single definition of a "small business." The SBA sets a size standard for each NAICS code, expressed either as a maximum number of employees or a maximum average annual revenue, depending on the industry. Whether you qualify as small for a given contract depends on the NAICS code attached to that contract — not on a one-size-fits-all rule.

This matters because small-business status is the gateway to set-aside contracts. The government has a statutory goal of awarding 23% of prime contract dollars to small businesses, and programs like 8(a) Business Development, WOSB, SDVOSB, and HUBZone are built on top of that small-business eligibility. If you want to compete for that reserved work, the NAICS codes on your registration — and the size standards tied to them — are foundational. To go deeper on the programs, see our guide to small-business set-asides.

Same company, different status

Because each NAICS code has its own size standard, you can qualify as a small business under one code and not under another. Always check the size standard for the specific code a contract uses before assuming you're eligible.

How to find and choose the right NAICS codes

Choosing codes isn't guesswork, but it does take a little research. The goal is to describe what you genuinely do — accurately and completely — without padding your list with codes that don't fit. Here's a sensible process:

1List what you actually sell. Write out your real lines of business, products, and services in plain language before you touch any code lookup.
2Search the NAICS system using keywords for each line of business to find candidate six-digit codes that match.
3Read the full code descriptions, not just the titles. The official descriptions spell out what is and isn't included, which prevents costly mismatches.
4Check the SBA size standard for each candidate code so you know how you'll be classified for contracts under it.
5Look at real solicitations in your field to see which codes contracting officers actually assign to the work you want.
6Pick your primary, then add the rest — choose the single code that best represents your core business, then add the additional codes that cover everything else you legitimately do.

Primary vs. additional NAICS codes

Your registration has one primary NAICS code plus as many additional codes as accurately apply. Your primary code is the one that best captures your main line of business — think of it as your headline. Additional codes broaden your reach so you can surface for, and be eligible for, work across everything else you do.

Two practical rules of thumb: don't under-list (too few codes and relevant opportunities never reach you), and don't over-list (codes for work you can't credibly perform can misrepresent your business and waste your time on poor-fit bids). Aim for an honest, complete picture. You set these codes when you register your entity — see how to register on SAM.gov for where NAICS codes fit into the full process — and you can update them as your business evolves.

Prefer to skip the research?

Picking the right codes, checking each size standard, and getting your entity set up correctly is exactly the kind of detail that trips owners up. Our done-for-you SAM.gov registration handles it end to end for a flat fee, so your codes are right the first time.

Codes set? Go find the contracts that match them.

Search live federal opportunities by NAICS code

After your codes are set: win the work

Accurate NAICS codes get you in front of the right opportunities, but they don't win contracts by themselves. Once your codes are surfacing relevant work, the next move is responding well — learn how to win government contracts as a small business so the matches your codes generate actually turn into awards.