491110 — Postal Service
Description
This industry comprises establishments primarily engaged in providing mail services under a universal service obligation. Mail services include the carriage of letters, printed matter, or mailable packages, including acceptance, collection, processing, and delivery. Due to the infrastructure requirements of providing mail service under a universal service obligation, postal service establishments often provide parcel and express delivery services in addition to the mail service. Establishments primarily engaged in performing one or more parts of the basic mail service, such as sorting, routing and/or delivery (except bulk transportation of mail) are included in this industry (as defined in the official U.S. Census Bureau 2022 NAICS Manual).
Exclusions & Cross-References
- Providing bulk transportation of mail on a contract basis to and from postal service establishments--are
- classified in Industry Group 4841, General Freight Trucking;
- Providing services outside of the basic mail service, such as mail presort, mail consolidation, or address bar
- coding services, on a contract or fee basis--are classified in U.S. Industry 561499, All Other Business
- Support Services;
- Providing courier services and express delivery of parcels without operating under a universal service
- obligation--are classified in Industry 492110, Couriers and Express Delivery Services;
- Providing mailbox services along with other business services--are classified in U.S. Industry 561431,
- Private Mail Centers; and
- Providing local messenger and delivery services--are classified in Industry 492210, Local Messengers and
- Local Delivery.
Overview Facts
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 4311 - United States Postal Service (via SIC1987:4311→NAICS1997:49111→2002:491110→2007:491110→2012:491110→2017:491110→2022:491110)
- SIC 7389 - Business Services (via SIC1987:7389→NAICS1997:49111→2002:491110→2007:491110→2012:491110→2017:491110→2022:491110)
Suggested Product Service Codes (Advisory)
The following Product Service Codes (PSCs) are advisory suggestions aligned with this NAICS code. Note: NAICS and PSC codes map to different dimensions of procurement (industry vs. product/service). There is no official binding 1:1 crosswalk.
- PSC V003 — Packing/Crating Services
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Frequently Asked Questions (FAQ)
Is NAICS code 491110 valid in 2022? ▾
Yes, 491110 is a valid 6-digit 2022 NAICS national industry code representing 'Postal Service' under Sector 48-49 in the official classification index.
What is the SBA size standard for NAICS code 491110? ▾
The Small Business Administration (SBA) has established a small business size standard of $9,000,000 for NAICS code 491110 (Postal Service), calculated based on receipts.
What is the legacy SIC equivalent for NAICS 491110? ▾
According to official Census Bureau concordance tables, NAICS code 491110 (Postal Service) maps to legacy 1987 Standard Industrial Classification (SIC) codes: 4311 - United States Postal Service, 7389 - Business Services.
Related Pages & Tools
Further regulatory reference links for NAICS code 491110:
- Sector 48-49 Directory Hub — List of related industries in the Transportation and Warehousing sector.
- SIC ↔ NAICS Crosswalk Tool — Look up mappings between legacy SIC codes and modern classifications.
- NAICS 491110 to SIC Crosswalk — Bidirectional mapping to legacy SIC codes (Postal Service).
- SBA Size Standards Guide — Complete rules and averaging periods for small business classifications.
- Calculating Annual Receipts Guide — Detailed worked example of revenue calculation rules.