AskKaka lists the STD code of New Delhi that is 011. New Delhi is a part of Delhi and the ISO code of Delhi state is DL.
New Delhi STD code aka subscriber trunk dialing code is 011 which is mentioned above on this page of AskKaka. We are great resource of finding New Delhi std code of Delhi (DL).
Useful Info :-
Please take a note that if you are in India and dialing a landline number of New Delhi then you will have to dial STD code 011 as a prefix followed by the phone number of a landline user and if you are calling New Delhi's phone number from a foreign country then you need to add +91 (the country code) followed by 11, e.g. +9111 (no need to add "0" as prefix) followed by the landline phone number.
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