NAICS vs. SIC Codes: What They Are and How Marketers Use Them

When building a B2B marketing list or trying to target businesses by industry, you’ll often see two acronyms: NAICS and SIC. These codes are the backbone of industry classification in the U.S.—and they’re essential tools for marketers looking to reach the right decision-makers.

But what do these codes actually mean? How are they different? And more importantly, how can you use them to sharpen your marketing strategy?

In this blog, we’ll explain:

• What NAICS and SIC codes are

• Key differences between the two

• How marketers use them for segmentation

• Where to find (or look up) these codes

• How Gemstone Data uses them to build powerful business lists

🏢 What Are NAICS and SIC Codes?

NAICS (North American Industry Classification System)

NAICS codes are 6-digit codes developed in 1997 by the U.S. government, Mexico, and Canada to classify businesses by their primary economic activity.

For example:

• 541611 = Administrative Management & General Consulting Services

• 236220 = Commercial & Institutional Building Construction

• 812112 = Beauty Salons

Each digit in the NAICS code adds specificity. A 2-digit code gives you the broad sector; each additional digit narrows it down further.

SIC (Standard Industrial Classification)

SIC codes are 4-digit industry codes developed in the 1930s by the U.S. government. Though now officially replaced by NAICS, SIC is still widely used in marketing and business databases.

For example:

• 7371 = Computer Programming Services

• 5812 = Eating Places (Restaurants)

• 6021 = National Commercial Banks

Even though NAICS is more modern and detailed, SIC remains popular because:

• Many older databases still use SIC

• Some industries are easier to target using SIC codes

• Many marketers are more familiar with SIC structure

🧠 What’s the Difference Between NAICS and SIC?

🔍 Why Marketers Use NAICS and SIC Codes

When building a B2B marketing list, you don’t just want any business—you want the right ones. NAICS and SIC codes let you filter by industry type and narrow your list to only those companies likely to buy what you're selling.

Common Use Cases:

• Target specific industries (e.g., auto dealers, construction firms, law offices)

• Run campaigns by sector (e.g., emailing manufacturers vs. medical practices)

• Qualify leads by industry relevance

• Suppress industries that aren’t a fit

• Match business types to service-specific solutions

Whether you're selling insurance, offering software, or marketing industrial equipment, NAICS and SIC codes are vital for segmentation.

📈 Example: Targeting Using Codes

Let’s say you sell a payroll solution for small businesses.

You might target:

• NAICS 541214 = Payroll Services

• SIC 8721 = Accounting, Auditing, and Bookkeeping Services

You could also suppress:

• NAICS 611110 = Elementary & Secondary Schools

• SIC 8011 = Offices and Clinics of Medical Doctors

This gives you precision targeting that dramatically improves your contact quality and conversion rates.

🗃 Where Can You Look Up NAICS and SIC Codes?

Several tools let you search for codes by keyword, industry, or company name:

NAICS Code Lookup:

• https://www.naics.com/search/

• https://www.census.gov/naics/

SIC Code Lookup:

• https://siccode.com/

• https://www.osha.gov/data/sic-search

You can also use these to match codes to company websites, competitors, or industry segments before building a lead list.

🧰 How Gemstone Data Uses NAICS and SIC Codes

At Gemstone Data, we use both NAICS and SIC classification systems to help our clients:

• Build hyper-targeted B2B lists

• Select industries based on product fit

• Filter by company size, location, revenue, or employee count

• Segment for email, telemarketing, direct mail, or omnichannel campaigns

For example:

• A commercial solar company may want NAICS 236220 (Commercial Construction)

• A marketing agency may want SIC 5812 (Restaurants) for local outreach

• An insurance firm may want NAICS 621610 (Home Health Care Services) for final expense products

Whatever the industry, we help clients choose the right code filters to ensure their campaign hits the mark.

🚩 Common Mistakes to Avoid

• Using only the 2-digit code: Too broad. Drill down to 4–6 digits for better precision.

• Targeting the wrong industry: Always double-check code definitions and examples.

• Mixing SIC and NAICS incorrectly: Some platforms or CRMs support one or the other—ensure consistency.

• Overlooking updates: NAICS codes are updated every 5 years. Make sure you're using the latest version.

🧠 Pro Tips for Marketers

• Combine NAICS/SIC filtering with other criteria like geography, business age, or digital presence.

• Use lookalike businesses (based on codes) to expand a winning campaign.

• Suppress competitors’ codes or irrelevant sectors to save ad spend.

• Don’t guess — use a data provider that helps you select codes accurately.

🧮 NAICS and SIC Code Examples (Quick Reference)

🚀 Final Thoughts

If you’re doing any kind of B2B outreach—whether via email, phone, direct mail, or mobile ads—NAICS and SIC codes are powerful tools for precision targeting.

They help you:
✔ Identify your best-fit industries
✔ Filter out irrelevant prospects
✔ Maximize ROI on every campaign
✔ Avoid wasting time on low-quality leads

But only if you use them correctly and strategically.

📞 Need Help Building a B2B List by NAICS or SIC Code?

At Gemstone Data, we make it easy to:

• Search businesses by NAICS or SIC codes

• Filter by revenue, employees, location, or business age

• Get real-time access to targeted B2B lists

• Export for email, telemarketing, or direct mail campaigns

👉 Contact us to build your custom business list today.