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.
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
| NAICS Code | 491110 |
|---|---|
| Industry Title | Postal Service |
| SBA Size Standard | $9,000,000 |
| U.S. Establishments | Not disclosed (Census CBP, 2023) |
| IRS PBA Code | None (none match) |
| Sectors Hierarchy | Sector 48-49 → 491 → 4911 |
| Source / Verified | US Census 2022 NAICS Manual, Census CBP / 2026-06-28 |
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)
Related Resources & Compliance Guides
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.
- SBA Size Standards Guide — Complete rules and averaging periods for small business classifications.
- Calculating Annual Receipts Guide — Detailed worked example of revenue calculation rules.
Related Industries in 4911
Frequently Asked Questions (FAQ)
Is 491110 a valid 2022 NAICS code?
NAICS 491110 is 'Postal Service', a 2022 U.S. national industry under Sector 48-49 (Transportation and Warehousing); the SBA small-business size standard is $9,000,000.
What is the SBA size standard for NAICS 491110?
The SBA small business size standard for NAICS 491110 is $9,000,000 (based on receipts).
What is the legacy SIC code mapping for 491110?
NAICS code 491110 maps to the legacy 1987 SIC codes: 4311 - United States Postal Service, 7389 - Business Services.