| | | | | | STD Numbers of Bihar | |
| | Bihar Areas | STD Codes | Bikram | 06135 | Bikramganj | 06185 | Birpur | 06471 | Buxer | 06183 | Chakai | 06347 | Chapara | 06152 | Dalsinghsarai | 06278 | Danapur | 06115 | Darbhanga | 06272 | Daudnagar | 06328 | Dhaka | 06250 | Dhamdaha | 06462 | Dumraon | 06323 | Ekma | 06155 | Forbesganj | 06455 | Gaya | 0631 | Gogri | 06245 | Gopalganj | 06156 | H.Kharagpur | 06342 | Hajipur | 06224 | Hathua | 06150 | Hilsa | 06111 |
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