| Area/District | Active Postcodes |
| DN1 | 1,146 |
| DN10 | 674 |
| DN11 | 958 |
| DN12 | 741 |
| DN14 | 1,999 |
| DN15 | 1,321 |
| DN16 | 869 |
| DN17 | 1,124 |
| DN18 | 444 |
| DN19 | 273 |
| DN2 | 714 |
| DN20 | 836 |
| DN21 | 1,656 |
| DN22 | 1,497 |
| DN3 | 851 |
| DN31 | 984 |
| DN32 | 917 |
| DN33 | 611 |
| DN34 | 557 |
| DN35 | 979 |
| DN36 | 714 |
| DN37 | 998 |
| DN38 | 122 |
| DN39 | 138 |
| DN4 | 1,666 |
| DN40 | 618 |
| DN41 | 272 |
| DN5 | 1,169 |
| DN55 | 60 |
| DN6 | 992 |
| DN7 | 760 |
| DN8 | 569 |
| DN9 | 849 |