When you travel to a new and unknown destination, it is always advisable to carry all the requisite things that will help you to explore it in a safe manner. A map of the city/ state you are traveling to and a catalog of the STD (Subscriber Trunk Dialing) & ISD (International Subscriber Dialing) codes of the place always comes handy. Generally, the STD code precedes the landline number of the person you are calling. This applies only when the caller and the receiver are located in different cities.
Likewise, if you calling on a fixed line number of any city in Bihar from overseas, you will need to add the ISD code of India and then the STD code of that particular city before the digits of the landline number. If you are dialing a mobile number in Bihar from abroad, you need to prefix the number with the ISD code (091) of India. Listed below are the STD and ISD codes of various places in Bihar. For your convenience, we have arranged the cities according to the alphabetical order they follow.