Telephone numbers in India are administered under the National Numbering Plan of 2003 by the Department of Telecommunications of the Government of India. The numbering plan was last updated in 2015. The country code "91" was assigned to India by the International Telecommunication Union in the 1960s.

Subscriber trunk dialling (STD), also known as subscriber toll dialing, is a telephone numbering plan feature and telecommunications technology in the United Kingdom and various Commonwealth countries for the dialling of trunk calls by telephone subscribers without the assistance of switchboard operators.