Navigating U.S. National Electrical Code Variations

18 Dec 2025

Why ETL Certification Works Across all Jurisdictions

If you operate facilities across multiple states, you've likely discovered a frustrating reality: the National Electrical Code (NEC) edition enforced in Texas might be completely different from the one enforced in California or New York. How can you ensure your equipment purchases work everywhere?

The State of NEC Adoption in 2025

As of October 1, 2025, the United States presents a patchwork of code enforcement:

• 20 states enforce the 2023 NEC
• 19 states enforce the 2020 NEC
• 5 states enforce the 2017 NEC
• 2 states still enforce the 2008 NEC

Even within states, local jurisdictions may adopt different editions. One city in Texas might enforce the 2023 code while a neighboring county still uses the 2020 version. For facility managers and equipment purchasers, this variation creates a significant challenge.

The Solution: Understanding "Listed" Equipment

Here's the good news: while NEC editions vary, the fundamental definition of "listed" equipment remains consistent across all versions. The NFPA 70 defines listed equipment as products included in a list published by an organization acceptable to the Authority Having Jurisdiction (AHJ).

This is where certification by an ANSI accredited organization like Intertek becomes invaluable. Equipment bearing the ETL mark has been:

• Tested to relevant safety standards
• Periodically inspected to demonstrate continued conformance to standard(s)
• Listed by a certification body recognized across North America

Why One Certification Works Everywhere

The key lies in how testing organizations operate. Intertek, as an ANSI accredited Certification Body, conducts evaluations based on applicable product safety standards—not on specific NEC editions. These safety standards (like NFPA 79 for industrial machinery) form the technical foundation that all NEC editions reference.

When Intertek certifies a product with the ETL mark, it's confirming that the product meets these underlying safety standards.

Real-World Application: Multi-State Operations

Imagine you're rolling out identical packaging lines across facilities in Houston, Phoenix, and Chicago. Each location might enforce a different NEC edition, therefore in addition to the delivered ETL Listed Mark on the packaging machine, the manufacturer would need to obey different code for each location targeted.

In each location, the local electrical inspector—serving as the AHJ—will recognize Intertek as an acceptable listing organization. They'll verify that:

• The complete machine is properly listed
• The ETL mark is visible and identifiable
• The installation meets local code requirements for wiring, protection, and access

The machine's certification doesn't change based on location. What changes are the specific installation requirements—wire sizing, overcurrent protection, and access provisions—which vary by local interpretation of their adopted NEC edition.

Practical Steps for Multi-Jurisdiction Operations

To simplify your equipment procurement and installation across different jurisdictions:

1. Standardize on recognized marks like ETL from Intertek, which are accepted universally
2. Focus on complete machine listings rather than worrying about individual component certifications
3. Understand that variations exist in installation requirements, not in the validity of the listing itself
4. Maintain documentation including access to the certification body's directory of listed products
5. Communicate early with local AHJs to understand their specific installation requirements

The Resource You Need

The NFPA provides helpful enforcement maps showing which NEC edition each jurisdiction has adopted. You can find these at https://www.nfpa.org/education-and-research/electrical/nec-enforcement-maps. While these maps show the variation in code adoption, they also underscore why working with universally accepted certification bodies is essential.

The Bottom Line

The variation in NEC editions across jurisdictions doesn't have to complicate your equipment purchasing decisions. By choosing equipment with ETL certification from Intertek—an ANSI accredited organization accepted by AHJs throughout the United States—you're ensuring your installations can proceed smoothly regardless of local code editions.

The ETL mark represents a commitment to safety that transcends individual code versions, giving you the flexibility to operate confidently across all fifty states. In a landscape of varying code adoption, that consistency is invaluable.