Here is a comprehensive list of STD (Subscriber Trunk Dialing) codes for various cities and towns in Bihar, India:
| City/Town | STD Code |
|---|---|
| Adhaura | 06180 |
| Amarpur | 06420 |
| Araria | 06453 |
| Areraj | 06258 |
| Arrah | 06182 |
| Arwal | 06337 |
| Aurangabad | 06186 |
| Bagaha | 06251 |
| Banka | 06424 |
| Banmankhi | 06467 |
| Barauni | 06279 |
| Barh | 06132 |
| Barsoi | 06451 |
| Begusarai | 06243 |
| Benipatti | 06271 |
| Benipur | 06242 |
| Bettiah | 06254 |
| Bhabhua | 06189 |
| Bhagalpur | 0641 |
| Bidupur | 06229 |
| Bihar Sharif | 06112 |
| Bikram | 06135 |
| Bikramganj | 06185 |
| Birpur | 06471 |
| Buxar | 06183 |
| Chakai | 06347 |
| Dalsinghsarai | 06278 |
| Danapur | 06115 |
| Darbhanga | 06272 |
| Daudnagar | 06328 |
| Gaya | 0631 |
| Hajipur | 06224 |
| Jamalpur | 06344 |
| Jamui | 06345 |
| Jehanabad | 06114 |
| Jhanjharpur | 06273 |
| Katihar | 06452 |
| Khagaria | 06244 |
| Kishanganj | 06466 |
| Lakhisarai | 06346 |
| Madhepura | 06476 |
| Madhubani | 06276 |
| Motihari | 06252 |
| Munger | 06344 |
| Muzaffarpur | 0621 |
| Nalanda | 06111 |
| Nawada | 06324 |
| Patna | 0612 |
| Purnia | 06454 |
| Rohtas | 06184 |
| Saharsa | 06478 |
| Samastipur | 06274 |
| Saran (Chhapra) | 06152 |
| Sheikhpura | 06341 |
| Sheohar | 06226 |
| Sitamarhi | 06226 |
| Siwan | 06154 |
| Supaul | 06473 |
| Vaishali | 06227 |
