| Area/District | Active Postcodes |
| M1 | 1,013 |
| M10 | 1,092 |
| M11 | 1,109 |
| M12 | 876 |
| M13 | 759 |
| M14 | 1,564 |
| M15 | 934 |
| M16 | 1,504 |
| M17 | 364 |
| M18 | 665 |
| M19 | 1,056 |
| M2 | 685 |
| M20 | 2,416 |
| M21 | 1,722 |
| M22 | 2,202 |
| M23 | 1,294 |
| M24 | 1,840 |
| M25 | 2,219 |
| M26 | 1,735 |
| M27 | 2,225 |
| M28 | 2,499 |
| M29 | 1,098 |
| M3 | 1,141 |
| M30 | 1,492 |
| M31 | 1,123 |
| M32 | 986 |
| M33 | 2,603 |
| M34 | 1,860 |
| M35 | 1,105 |
| M38 | 507 |
| M4 | 785 |
| M40 | 1,778 |
| M41 | 1,381 |
| M43 | 739 |
| M44 | 578 |
| M45 | 1,000 |
| M46 | 685 |
| M5 | 1,496 |
| M50 | 335 |
| M52 | 81 |
| M6 | 1,185 |
| M60 | 1,524 |
| M61 | 318 |
| M7 | 1,607 |
| M8 | 1,807 |
| M9 | 1,952 |
| M90 | 244 |
| M99 | 36 |