AskKaka lists the STD code of Kolkata that is 033. Kolkata is a part of West Bengal and the ISO code of West Bengal state is WB.
Kolkata STD code aka subscriber trunk dialing code is 033 which is mentioned above on this page of AskKaka. We are great resource of finding Kolkata std code of West Bengal (WB).
Useful Info :-
Please take a note that if you are in India and dialing a landline number of Kolkata then you will have to dial STD code 033 as a prefix followed by the phone number of a landline user and if you are calling Kolkata's phone number from a foreign country then you need to add +91 (the country code) followed by 33, e.g. +9133 (no need to add "0" as prefix) followed by the landline phone number.
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