US Standard Industrial Classification (SIC) Code Lookup

Division: D - Manufacturing

US-SIC Code 3661 - Telephone and Telegraph Apparatus

Industry Description

Establishments primarily engaged in manufacturing wire telephone and telegraph equipment. Included are establishments manufacturing modems and other telephone and telegraph communications interface equipment. Establishments primarily engaged in manufacturing cellular radio telephones are classified in Industry 3663.

Business Examples

Common types of business activities within US SIC 3661 - Telephone and Telegraph Apparatus are:

  • Auto-transformers for telephone switchboards
  • Carrier equipment, telephone and telegraph
  • Communications headgear, telephone
  • Data sets, telephone and telegraph
  • Facsimile equipment
  • Headsets, telephone
  • Message concentrators
  • Modems
  • Multiplex equipment, telephone and telegraph
  • Switchboards, telephone and telegraph
  • Switching equipment, telephone
  • Telegraph office switching equipment
  • Telephone answering machines
  • Telephone central office equipment, dial and manual
  • Telephone dialing devices, automatic
  • Telephone sets, except cellular radio telephone
  • Telephone station equipment and parts, wire
  • Telephones underwater
  • Telephones, sound powered (no battery)
  • Toll switching equipment, telephone

IBISWorld Industry Research Report

Telecommunications Networking Equipment Manufacturing in the US (33421)

Revenue 2025

$4.5bn

Growth 2025

-0.87%

Key Trends

  • Imports have been a major threat to the industry over the past five years

  • A shift towards outsourcing network manufacturing to low-wage companies is enabling international trade to grow rapidly

  • Manufacturers are shifting to designing and developing higher-margin networking equipment

Products and Services

View more report data

US-SIC Hierarchy 3661 - Telephone and Telegraph Apparatus

US-SIC Code 3661 - Telephone and Telegraph Apparatus sits in the 2-digit Telephone and Telegraph Apparatus sector. US SIC codes can be 2 to 8 digits and the further along the hierarchy, the more detailed and specific the category will be.

Division: D

Division Title: Manufacturing

2 Digits 3 Digits 4 Digits

Extended US-SIC Hierarchy for 3661 - Telephone and Telegraph Apparatus

For business marketing and targeting, US SIC Codes have been extended to provide more specific classifications within US-SIC 3661 - Telephone and Telegraph Apparatus. Extended US SIC Codes are being continuously updated to reflect the current business environment.

6 Digit SIC Codes

  • 366101 Telephone auto answer equipment-mfrs
  • 366102 Telephone equipment & systems-mfrs
  • 366103 Telephone booths (manufacturers)
  • 366198 Telephone & telegraph apparatus (mfrs)

8 Digit SIC Codes

  • 36610000 Telephone and telegraph apparatus
  • 36610100 Telephones and telephone apparatus
  • 36610101 Autotransformers for telephone switchboards
  • 36610102 Communication headgear, telephone
  • 36610103 Facsimile equipment
  • 36610104 Headsets, telephone
  • 36610105 Modems
  • 36610106 Switching equipment, telephone
  • 36610107 Telephone answering machines
  • 36610108 Telephone central office equipment, dial or manual
  • 36610109 Telephone dialing devices, automatic
  • 36610110 Telephone sets, all types except cellular radio
  • 36610111 Telephone station equipment and parts, wire
  • 36610112 Telephones, sound powered (no battery)
  • 36610113 Telephones, underwater
  • 36610114 Toll switching equipment, telephone
  • 36610200 Telegraph and related apparatus
  • 36610201 PBX equipment, manual or automatic
  • 36610202 Telegraph office switching equipment
  • 36610203 Telegraph or telephone carrier and repeater equipment
  • 36610204 Telegraph station equipment and parts, wire
  • 36619900 Telephone and telegraph apparatus, nec
  • 36619901 Carrier equipment, telephone or telegraph
  • 36619902 Data sets, telephone or telegraph
  • 36619903 Electronic secretary
  • 36619904 Message concentrators
  • 36619905 Multiplex equipment, telephone and telegraph
  • 36619906 Switchboards, telephone or telegraph
  • 36619907 Telephone cords, jacks, adapters, etc.
  • 36619908 Fiber optics communications equipment

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US SIC Code Directory

Each US SIC Code is part of a Division, which corresponds with a numerical range. Select a Division category from the table below, then drill down to discover the industries within that Division.

Division US-SIC Code Sector title
A 01-09 Agriculture, Forestry, and Fishing
B 10-14 Mining
C 15-17 Construction
D 20-39 Manufacturing
E 40-49 Transportation, Communications, Electric, Gas, and Sanitary Services
F 50-51 Wholesale Trade
G 52-59 Retail Trade
H 60-67 Finance, Insurance, and Real Estate
I 70-89 Services
J 90-99 Public Administration

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