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Compliance Guides

Compiled & reviewed by the EntityCodes Editorial Team (Tech Labs FZ LLC) · Data verified: 2026-06-28

Detailed manuals, regulatory frameworks, and worked examples for corporate identifiers and classification codes.

NAICS Codes Explained: Structure, Hierarchy, and Purpose

A comprehensive foundational overview explaining what NAICS codes are, how their hierarchy works, and how federal agencies use them.

Deep-Dive Topics

How to Find and Verify Your Business NAICS Code A step-by-step practical guide to looking up and selecting the correct NAICS code for an organization using self-classification rules. NAICS 2017 to 2022 Updates: Key Changes, Splits, and Mergers An analytical breakdown of the major changes introduced in the 2022 NAICS revision, detailing merged codes and retired classifications. NAICS vs. SIC vs. ISIC: Understanding Industrial Classification Systems A comparative analysis explaining the relationship, scope, and differences between NAICS, legacy SIC, and the international UN ISIC standard. How NAICS Codes Affect Your Business Tax Filings and SBA Status Guides small businesses on how their NAICS classification dictates IRS business activity coding and federal contracting programs. Are NAICS Codes State-Specific? National vs. State Classifications Explains why NAICS is a federal standard, not state-issued, and how businesses lookup and report their codes to state departments. Do I Need a NAICS Code for My LLC? Registration and Compliance Requirements Explains when state LLC registrations, business bank accounts, and tax returns require a valid NAICS industry code.

How to Verify a Business: Official 50-State SOS & Federal Directory

Complete guide and directory for verifying U.S. business registration. Links to all 50 Secretary of State business search portals, SEC EDGAR, and GLEIF LEI lookup.

SIC Codes Explained: History, Structure, and Concordances

The complete history and structural layout of the 1987 Standard Industrial Classification (SIC) system, including its legacy role.

Deep-Dive Topics

How to Verify a Business: Official 50-State SOS & Federal Directory

Complete guide and directory for verifying U.S. business registration. Links to all 50 Secretary of State business search portals, SEC EDGAR, and GLEIF LEI lookup.

SBA Size Standards: A Complete Guide to Small Business Compliance

An authoritative guide to the Small Business Administration (SBA) size standard table, outlining its legal role in government contracting.

Deep-Dive Topics

Receipts-Based vs. Employee-Based SBA Size Standards Explained A breakdown of the two primary measurement bases used by the SBA, explaining when employee counts vs. revenue averages apply. How to Calculate Average Annual Receipts for SBA Certification Instructions on calculating annual receipts according to SBA regulations, detailing the 3-year and 5-year average calculation rules. Understanding SBA Affiliation Rules and How They Impact Business Size Explains how shared ownership, management, or contracts create affiliation, requiring businesses to merge receipts for size calculations. SBA Size Protests: Eligibility, Filing, and Appeals Processes A compliance overview detailing how competitors challenge small business self-certifications and how to defend against size protests. Are SBA Size Standards Different by State? Federal Uniformity Rules Explains the nationwide uniformity of Small Business Administration (SBA) size standard limits across all 50 states.

How to Verify a Business: Official 50-State SOS & Federal Directory

Complete guide and directory for verifying U.S. business registration. Links to all 50 Secretary of State business search portals, SEC EDGAR, and GLEIF LEI lookup.

U.S. Federal Contracting Identifiers: DUNS, UEI, and CAGE Guide

A comprehensive reference detailing the required structural identifiers needed to transact with the U.S. federal government.

How to Verify a Business: Official 50-State SOS & Federal Directory

Complete guide and directory for verifying U.S. business registration. Links to all 50 Secretary of State business search portals, SEC EDGAR, and GLEIF LEI lookup.

Legal Entity Identifier (LEI): Global Financial Identity Standards

A comprehensive guide on the international Legal Entity Identifier (LEI) system and its regulatory role in global finance.

How to Verify a Business: Official 50-State SOS & Federal Directory

Complete guide and directory for verifying U.S. business registration. Links to all 50 Secretary of State business search portals, SEC EDGAR, and GLEIF LEI lookup.

Guides Hub Frequently Asked Questions

What subjects are covered in these compliance guides? ▾

These compliance guides cover NAICS code structures, legacy SIC system classifications, SBA small business size definitions, IRS PBA tax activity codes, and federal identifiers like UEI, CAGE, and LEI.

How often are the regulatory guides updated? ▾

The guides are updated continuously in alignment with federal updates, such as the five-year Census NAICS updates, SBA size standard inflation adjustments, and DLA CAGE address guidelines.

Are these compliance guides official government publications? ▾

No, these guides are independent educational and compliance references compiled by entitycodes.org, citing official public-domain resources for verification.

How can I calculate small business size eligibility using the guides? ▾

You can follow our 'SBA Size Standards Guide' and 'Calculating Annual Receipts Guide', which detail the formulas to average your gross receipts over five fiscal years.

What is the transition from DUNS numbers to Unique Entity IDs? ▾

As explained in our transition guide, the GSA retired the proprietary DUNS number on April 4, 2022, replacing it with the government-owned Unique Entity ID (UEI) system in April 2022.

How do I request a CAGE code based on the guides? ▾

Our guides outline the steps to submit your company profile in SAM.gov, which automatically transmits your address information to the DLA to trigger CAGE code assignment.

What standard governs the global Legal Entity Identifier (LEI)? ▾

The LEI is structured under the ISO 17442 international standard, as detailed in our 'Legal Entity Identifier Guide', which explains the role of GLEIF and issuing LOUs.

How does our crosswalk guide map SIC codes to NAICS? ▾

The crosswalk guide outlines the transitive chaining method, linking legacy 1987 SIC codes step-by-step through successive NAICS revisions to active 2022 codes.

Does my LLC need a NAICS code according to the tutorials? ▾

Our LLC registration guide explains that while state filings vary, a NAICS code is practically required to open business bank accounts and validate IRS Schedule C tax returns.

Where do I find the official source databases cited in the guides? ▾

Each guide lists the official publishers (including Census Bureau, SBA, IRS, DLA, and GLEIF) and provides direct links to the primary reference registries.

Sources & References

  1. U.S. Census Bureau: North American Industry Classification System (NAICS) Manual
  2. U.S. Occupational Safety and Health Administration (OSHA): Standard Industrial Classification (SIC) Manual
  3. U.S. Small Business Administration (SBA): Table of Small Business Size Standards
  4. Electronic Code of Federal Regulations (eCFR): 13 CFR Part 121 - Small Business Size Regulations
  5. U.S. General Services Administration (GSA): System for Award Management (SAM.gov) Unique Entity ID Guide
  6. Defense Logistics Agency: Defense Logistics Agency (DLA) CAGE Search and Registration
  7. U.S. Securities and Exchange Commission (SEC): SEC EDGAR Filer Standard Industrial Classification Codes
  8. Internal Revenue Service (IRS): Instructions for Schedule C (Form 1040) Principal Business Activity (PBA) Codes
  9. Global Legal Entity Identifier Foundation (GLEIF): GLEIF Golden Copy and Reference Data Registry
  10. Acquisition.gov: Federal Acquisition Regulation (FAR) Part 19 - Small Business Programs