How To Pick Your NAICS Code (And Why It Actually Matters)

Updated: August 2026 · Industry Advisors · Education, not legal or tax advice.

The NAICS code is one of those setup decisions founders often make in ten seconds and regret in year two. It shows up on your tax return, your business bank application, your state filings, your insurance quotes, and — if you ever apply for one — your SBA loan. Get it wrong and you'll spend an hour a year explaining why the code doesn't match what you actually do.

Here is what NAICS is, where it matters, and how to pick correctly the first time.

What NAICS Is

NAICS — the North American Industry Classification System — is a six-digit code that categorizes businesses by their primary economic activity. It replaced the older SIC code system in 1997 and is jointly maintained by the US, Canada, and Mexico. There are roughly 1,000 codes covering every legal industry.

The first two digits identify the broad sector (54 = Professional, Scientific, and Technical Services). Each additional digit narrows the classification: 5418 = Advertising, PR, and Related Services; 541810 = Advertising Agencies.

Where NAICS Shows Up

• IRS tax returns. Schedule C, Form 1065, Form 1120-S, Form 1120 all ask for the six-digit code. It informs which industry averages the IRS compares your return against.
• State registrations. Most states require a NAICS code on the Articles of Organization or on the state tax registration.
• Business bank applications. Banks use the code for risk-tier assessment. Certain codes are flagged high-risk (money services, cannabis-adjacent, adult, crypto).
• Insurance quotes. General liability, professional liability, and workers' comp all price on classification codes that map to NAICS. A wrong code can double the premium.
• SBA loans. The Small Business Administration's size standards (what counts as "small business") are defined by NAICS code.
• Government contracting. Federal contracts are set aside by NAICS. If you're planning to bid on federal work, the code is central.
• Marketplace and payment-processor risk assessment. Stripe, Square, PayPal, and Amazon all evaluate risk partly by industry code.

How To Pick Correctly

Step 1 · Search On The Official Census Tool

Go to naics.com/search or the official Census NAICS search at census.gov/naics. Type a keyword — what you actually do — and browse the results. Do not accept the first result; read the definitions.

Step 2 · Match On Your Primary Revenue Source

NAICS is chosen based on the activity that generates the largest share of your revenue. A design agency that also sells templates on the side is 541430 Graphic Design Services, not 454110 Electronic Shopping, even though templates go through a store.

Step 3 · Pick The Most Specific Applicable Code

The six-digit codes are more precise than four-digit codes. Insurance carriers and banks look at all six. A vague code invites follow-up questions.

Step 4 · Verify Against Your Service Model

Some common miscodings:

• SaaS startups often use 541511 Custom Computer Programming Services when the right code is 511210 Software Publishers — the difference is whether you build custom or sell a product.
• Consultants often use 541611 Administrative Management Consulting when a specialty code like 541614 Process/Physical Distribution Consulting fits better.
• Freelance content creators often use vague codes when 711510 Independent Artists, Writers, and Performers is a clean fit.

What If You Have Multiple Revenue Streams

You can only report one NAICS code per return. Pick the primary revenue source. If revenue streams shift meaningfully in year two, update the code on next year's return.

Some registrations (business licenses, insurance policies) allow multiple codes — use that flexibility where offered.

How To Change Your NAICS Code

On IRS returns — just use the new code on next year's Schedule C or 1120-S. No separate filing required.

On state filings — update through the state Department of Revenue portal, typically at no cost.

On business bank accounts — email your banker with the update; some banks will re-run risk screening.

On insurance policies — notify your broker; premium usually gets re-quoted.

Codes That Trigger Extra Scrutiny

Some NAICS codes are automatic red flags for banks, payment processors, and some insurers. Pick these only if they genuinely describe what you do:

• 522390 Other Activities Related to Credit Intermediation — money-services flag
• 523930 Investment Advice
• 713210 Casinos
• 424820 Wine and Distilled Alcoholic Beverage Merchant Wholesalers
• 111998 All Other Miscellaneous Crop Farming — sometimes flagged if the state permits cannabis

None of these are illegal or unavailable — they just require additional underwriting.

The One-Line Summary

Pick the most specific six-digit NAICS code that matches your primary revenue source. Save the code somewhere durable — you will reference it on tax returns, bank accounts, and insurance forms for as long as the LLC exists.

The Everyday Owner's Blueprint includes NAICS-code selection in Week 5, with a decision tree for common founder profiles and a list of codes to avoid unless they genuinely fit.

Industry Advisors · 30 Wall Street, New York, NY 10005. Education, not legal or tax advice.