CM
28 districts, 18,628 postcodes
Chelmsford, Braintree, Brentwood, Maldon, Uttlesford, Harlow, and others
| District | Postcodes | Local authority |
|---|---|---|
| CM0 | 561 | Maldon |
| CM1 | 1,558 | Chelmsford |
| CM11 | 450 | Basildon |
| CM12 | 508 | Basildon |
| CM13 | 701 | Brentwood |
| CM14 | 618 | Brentwood |
| CM15 | 596 | Brentwood |
| CM16 | 639 | Epping Forest |
| CM17 | 530 | Harlow |
| CM18 | 431 | Harlow |
| CM19 | 394 | Harlow |
| CM2 | 1,313 | Chelmsford |
| CM20 | 632 | Harlow |
| CM21 | 320 | East Hertfordshire |
| CM22 | 555 | Uttlesford |
| CM23 | 1,193 | East Hertfordshire |
| CM24 | 274 | Uttlesford |
| CM3 | 1,589 | Chelmsford |
| CM4 | 442 | Brentwood |
| CM5 | 449 | Epping Forest |
| CM6 | 987 | Uttlesford |
| CM7 | 1,345 | Braintree |
| CM77 | 461 | Braintree |
| CM8 | 920 | Braintree |
| CM9 | 1,055 | Maldon |
| CM92 | 18 | Harlow |
| CM98 | 19 | Chelmsford |
| CM99 | 70 | Chelmsford |