NAICS Code 523991 — Trust, Fiduciary, and Custody Activities

National Industry in the official 2022 North American Industry Classification System (U.S. Census Bureau). It is one of 2 national industries under 52399 (All Other Financial Investment Activities).

Code	523991
Title	Trust, Fiduciary, and Custody Activities
Level	National Industry (6-digit)
Edition	NAICS 2022 edition
SBA size standard	$47 million in average annual receipts

Official definition (2022 NAICS)

This U.S. industry comprises establishments primarily engaged in providing trust, fiduciary, and custody services to others, as instructed, on a fee or contract basis, such as bank trust offices and escrow agencies (except real estate).

Cross-References.

Is a business under 523991 "small"?

Under the SBA size standards (13 CFR 121.201, effective March 17, 2023), a business classified in NAICS 523991 qualifies as a small business if it does not exceed $47 million in average annual receipts. Small-business status determines eligibility for federal set-aside contracts, SAM.gov certifications and SBA loan programs — receipts are averaged over the latest 5 fiscal years.

Where 523991 sits in the hierarchy

Level	Code	Title
Sector	52	Finance and Insurance
Subsector	523	Securities, Commodity Contracts, and Other Financial Investments and Related Activities
Industry Group	5239	Other Financial Investment Activities
NAICS Industry	52399	All Other Financial Investment Activities
National Industry	523991	Trust, Fiduciary, and Custody Activities

Related SIC codes

Via the official U.S. Census concordance (1987 SIC ↔ NAICS), shown only where the industry definition is unchanged in NAICS 2022.

SIC code	Title
6091	Non-deposit Trust Facilities
6099	Functions Related to Depository Banking, Not Elsewhere Classified
6289	Services Allied With the Exchange of Securities or Commodities, Not Elsewhere Classified
6733	Trusts, Except Educational, Religious, and Charitable

Related National Industry codes

• 523999 — Miscellaneous Financial Investment Activities

Data: official 2022 NAICS structure, descriptions and Census concordances, U.S. Census Bureau — U.S. government works in the public domain (17 U.S.C. §105). Suggested reference, not an official determination.