Telephone numbers in India operator as well as the service and the company. Telemarketers have been issued 10-digit telephone numbers starting with 140 (140XXXXXXX) by the Department of Telecommunications on TRAI's request. Telephone numbers in India Telephone numbers in India are administered under the "National Numbering Plan of 2003" by the Department of Telecommunications. The numbering plan was last updated in 2015. The International Telecommunication Union has assigned the country calling code "91" to India. Subscriber Trunk Dialling (STD) codes are assigned to each city/town/village, with the larger Metro cities having shorter area codes (STD codes), which are from 2 to 8 digits long.
Subscriber trunk dialling dialled direct, the term has fallen into disuse. When telephone systems were first introduced, subscribers called a telephone exchange and asked a human operator to connect the call to another subscriber on the same exchange; calls to other exchanges were originally not possible. Later it became possible to dial numbers on the same exchange; calls to other exchanges (trunk calls) were possible, but had to be connected by an operator. When subscribers in one area became able to dial non-local subscribers, the term used for the innovation was subscriber trunk dialling. In the UK, STD started before 5 December 1958