The Area Codes of Mongolia:
| City/Town or Region | Area code | |
|---|---|---|
| 1. | Dadal | 5649 (+976 5649) |
| 2. | Dalanjargalan | 5243 (+976 5243) |
| 3. | Dalanzadgad city | 532 (+976 532) |
| 4. | Dariganga | 5143 (+976 5143) |
| 5. | Darkhan (Bor-Öndör) | 5651 (+976 5651) |
| 6. | Darkhan city | 372 (+976 372) |
| 7. | Darvi | 4344 (+976 4344) |
| 8. | Darvi | 4845 (+976 4845) |
| 9. | Dashbalbar (Erdes) | 5846 (+976 5846) |
| 10. | Dashinchilen | 3446 (+976 3446) |
| 11. | Davst | 4543 (+976 4543) |
| 12. | Delger (Guulin) | 4846 (+976 4846) |
| 13. | Delgerekh | 5244 (+976 5244) |
| 14. | Delgerkhaan | 2756 (+976 2756) |
| 15. | Delgerkhaan | 5652 (+976 5652) |
| 16. | Delgerkhangai | 5945 (+976 5945) |
| 17. | Delgertsogt | 5946 (+976 5946) |
| 18. | Delüün | 4247 (+976 4247) |
| 19. | Deren | 5947 (+976 5947) |
| 20. | Dörgön | 4345 (+976 4345) |
| 21. | Dörvöljin | 4646 (+976 4646) |
| 22. | Duut | 4346 (+976 4346) |