There are 24 post offices under PIN code 121004.
| Post Office | Office Type | Delivery Status | Taluk | District | Division | Region | State | Circle | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Amarpur B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 2 | Atali B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 3 | Ballabgarh S.O | Sub Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 4 | Baroli B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 5 | Chawla Colony Ballabgarh S.O | Sub Office | Non-Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 6 | Chhainsa B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 7 | Dayalpur B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 8 | Deeg B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 9 | Dhauj B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 10 | E C Dhauj S.O | Sub Office | Non-Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 11 | Faridabad Sector 3 S.O | Sub Office | Non-Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 12 | Fatehpur Billoch B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 13 | Fatehpur Tagga B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 14 | Gadpuri B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 15 | Gonchhi B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 16 | Jawan B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 17 | Machhgar B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 18 | Mohna B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 19 | N.T.P.C./sector-10 Faridabad S.O | Sub Office | Non-Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 20 | Neemka B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 21 | Pali B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 22 | Panhera Khurd B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 23 | Sagarpur B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |
| 24 | Seekri B.O | Branch Office | Delivery | Ballabgarh | Faridabad | Faridabad | Ambala Hq | Haryana | Haryana |