NAICS 523991 to SIC Code Crosswalk
The NAICS code 523991 (Trust, Fiduciary, and Custody Activities) maps transitively to legacy 1987 SIC classification code(s): 6091, 6099, 6289, 6733.
Concordance Concordance Mapping Asset
| Source Code | Source Industry | Target Code | Target Industry | Relation | Concordance Path |
|---|---|---|---|---|---|
| NAICS 523991 | Trust, Fiduciary, and Custody Activities | SIC 6091 | Nondeposit Trust Facilities | Many-to-Many | SIC1987:6091 → NAICS1997:523991 → 2002:523991 → 2007:523991 → 2012:523991 → 2017:523991 → 2022:523991 |
| NAICS 523991 | Trust, Fiduciary, and Custody Activities | SIC 6099 | Functions Related to Depository Banking, NEC | Many-to-Many | SIC1987:6099 → NAICS1997:523991 → 2002:523991 → 2007:523991 → 2012:523991 → 2017:523991 → 2022:523991 |
| NAICS 523991 | Trust, Fiduciary, and Custody Activities | SIC 6289 | Services Allied With the Exchange of Securities or Commodities, NEC | Many-to-Many | SIC1987:6289 → NAICS1997:523991 → 2002:523991 → 2007:523991 → 2012:523991 → 2017:523991 → 2022:523991 |
| NAICS 523991 | Trust, Fiduciary, and Custody Activities | SIC 6733 | Trusts, Except Educational, Religious, and Charitable | Many-to-Many | SIC1987:6733 → NAICS1997:523991 → 2002:523991 → 2007:523991 → 2012:523991 → 2017:523991 → 2022:523991 |
Why Concordances Don't Line Up 1:1
The Standard Industrial Classification (SIC) system was established in 1937 and last updated in 1987, organizing businesses by end products. The North American Industry Classification System (NAICS) replaced it in 1997, classifying establishments by production processes. Because of this structural shift, many-to-many relationships are common, requiring chained concordance steps to bridge the historical gap.
Reverse Crosswalk: Going the other way? See the mapping at SIC 6091 to NAICS, SIC 6099 to NAICS, SIC 6289 to NAICS, SIC 6733 to NAICS.
Related Pages & Tools
- NAICS Code 523991 Profile — Official definition, SBA size standards, and establishment statistics.
- Sector 52 Hub (Finance and Insurance) — Category directories.
- Interactive Crosswalk Engine — Convert any SIC or NAICS code dynamically.
Primary Ingestion Source
Data sourced from the U.S. Census Bureau Concordances (1997, 2002, 2007, 2012, 2017, and 2022 editions). Last verified on 2026-06-30.