Postal, telegraph and telephone service in the context of "Telkom Indonesia"

A telecommunications company is a kind of electronic communications service provider, more precisely a telecommunications service provider (TSP), that provides telecommunications services such as telephony and data communications access. Many traditional solely telephone companies now function as internet service providers (ISPs), and the distinction between a telephone company and ISP has tended to disappear completely over time, as the current trend for supplier convergence in the industry develops. Additionally, with advances in technology development, other traditional separate industries such as cable television, Voice-over IP (VoIP), and satellite providers offer similar competing features as the telephone companies to both residential and businesses leading to further evolution of corporate identity have taken shape.

Due to the nature of capital expenditure involved in the past, most telecommunications companies were government-owned agencies or privately owned monopolies operated in most countries under close state regulation. But today there are many private players in most regions of the world, and even most of the government-owned companies have been opened up to competition in-line with World Trade Organization (WTO) policy agenda. Historically, these government agencies were often referred to, primarily in Europe, as PTTs (postal, telegraph and telephone services). Telecommunications companies are common carriers, and in the United States are also known as local exchange carriers. With the advent of mobile telephony, telecommunications companies now include wireless carriers, or mobile network operators and even satellite providers (Iridium).

NTT, Inc. (formerly known as Nippon Telegraph and Telephone Corporation) is a Japanese telecommunications holding company headquartered in Tokyo, Japan. Ranked 128th in Fortune Global 500, NTT is the sixth largest telecommunications company in the world in terms of revenue, as well as the 15th largest publicly traded company in Japan by market cap, and the 6th largest by revenue, as of November 2025. In 2025, the company was ranked 79th in the Forbes Global 2000. NTT was the world's largest company by market capitalization in the late 1980s, and remained among the world's top 10 largest companies by market capitalization until the burst of the Dot-com bubble in the early 2000s.

The company traces its origin to the national telegraph service established in 1868, which came under the purview of the Ministry of Communications in the 1880s as part of a postal, telegraph and telephone service. In 1952, the telegraph and telephone services were spun off as the government-owned Nippon Telegraph and Telephone Public Corporation. Under Prime Minister Yasuhiro Nakasone, the company was privatised in 1985 along with the Japan Tobacco and Salt Public Corporation and subsequently the Japanese National Railways two years later, adopting the previous name until July 2025. While NTT has been listed on the Tokyo Stock Exchange since 1987, the Japanese government still owns roughly one-third of NTT's shares, regulated by the NTT Law (Law Concerning Nippon Telegraph and Telephone Corporation, Etc.).

The Ministry of Communications (逓信省, Teishin-shō) was a Cabinet-level ministry in the Empire of Japan, operating a postal, telegraph and telephone service. Its modern successors include the Ministry of Internal Affairs and Communications, Japan Post Holdings and NTT.

PTT, an abbreviation for Posta ve Telgraf Teşkilatı (lit. Post and Telegraph Agency), is the national post and telegraph directorate of Turkey. Formerly, the organization was named Posta Telgraf Telefon. After the privatization of the telephone telecommunications service business, the directorate was renamed, keeping its acronym. It is headquartered in Ankara, and is known as Turkish Post internationally.

Koninklijke KPN N.V. (Royal KPN N.V. in English), trading as KPN is a Dutch telecommunications company. KPN originated from a government-run postal, telegraph and telephone service and is based in Rotterdam, Netherlands.