A telephone company , also known as a telco , telephone service provider ,  or telecommunications operator , is a kind of communications service provider (CSP) (more precisely a telecommunications service provider or TSP) that provides telecommunications services such as telephony and data communications access. Many telephone companies were at one time government agencies or privately owned but state-regulated monopolies . The government agencies are often referred to, primarily in Europe, as PTTs ( postal, telegraph and telephone services ). 
Telephone companies are common carriers , and in the United States are also called local exchange carriers . With the advent of mobile telephony , telephone companies now include wireless carriers , or mobile network operators . 
Most telephone companies now also function as internet service providers (ISPs), and the distinction between a telephone company and an ISP may disappear completely over time, as the current trend for supplier convergence in the industry continues. 
- Comedian Lily Tomlin frequently satirized the telephone industry (and the country's then-dominant Bell System in particular) with a skit playing the telephone operator Ernestine. Ernestine, who became one of Tomlin's trademark characters, was perhaps most famous for the following line: "We don't care; we don't have to. We're the phone company."
- In the satirical 1967 film The President's Analyst , "TPC, The Phone Company", is depicted as plotting to enslave humanity by replacing landlines with implanted mobile phones .
- In the 1988 video game Zak McKracken and the Alien Mindbenders , The Phone Company (TPC) was used by the Caponian aliens to secretly reduce the intelligence of humans.
- Bell Telephone Company , forerunner of AT&T in the U.S.
- Internet telephony service provider
- Competitive local exchange carrier (in Canada and the U.S.)
- Communications service provider
- History of the telephone
- Incumbent local exchange carrier (of the Bell System)
- List of telephone operating companies
- List of mobile network operators
- Mobile network operator
- Plain old telephone service (POTS)
- Public switched telephone network
- Telecommunications Industry Association (for the development of U.S. telecom standards)
- Regional Bell Operating Company (in the U.S.)
- Service provider
- Telecommunications service provider
- The Phone Company , free, non-commercial email-to-fax service