Telephone numbers in India 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. For example, Tier-2 Cities or culturally significant towns in India have STD code with 3 digits. For example, Kanpur and Lucknow were the two cities between which the
Telephone prefix Telephone prefix A telephone prefix is the first set of digits after the country, and area codes of a telephone number; in the North American Numbering Plan countries (country code +# ), it is the first three digits of a seven-digit phone number, 3-3-4 scheme. In other countries both the prefix and the number may have different lengths. It shows which exchange the remaining numbers refer to. A full telephone number is usually made up of country code (required for international calls only), area code (required for calls between telephone areas), prefix, and subscriber number. Some places restrict certain prefixes