NN
19 districts, 17,126 postcodes
West Northamptonshire, North Northamptonshire, Buckinghamshire, Bedford, Cherwell, Stratford-on-Avon, and others
| District | Postcodes | Local authority |
|---|---|---|
| NN1 | 832 | West Northamptonshire |
| NN10 | 858 | North Northamptonshire |
| NN11 | 1,182 | West Northamptonshire |
| NN12 | 822 | West Northamptonshire |
| NN13 | 565 | West Northamptonshire |
| NN14 | 1,218 | North Northamptonshire |
| NN15 | 949 | North Northamptonshire |
| NN16 | 899 | North Northamptonshire |
| NN17 | 908 | North Northamptonshire |
| NN18 | 658 | North Northamptonshire |
| NN2 | 803 | West Northamptonshire |
| NN29 | 280 | North Northamptonshire |
| NN3 | 1,315 | West Northamptonshire |
| NN4 | 981 | West Northamptonshire |
| NN5 | 887 | West Northamptonshire |
| NN6 | 1,186 | West Northamptonshire |
| NN7 | 856 | West Northamptonshire |
| NN8 | 1,252 | North Northamptonshire |
| NN9 | 675 | North Northamptonshire |