Sectors in CM21
| Sector | Main place | Postcodes |
|---|---|---|
| CM21 0 | Sawbridgeworth | 136 |
| CM21 1 | Sawbridgeworth | 8 |
| CM21 9 | Sawbridgeworth | 175 |
Places covered by CM21
- Sawbridgeworth East Hertfordshire · 270
- High Wych East Hertfordshire · 18
- Allen's Green East Hertfordshire · 3