NN postcode district map, Northampton
Supplier statuses last checked .
The NN postcode area covers 19 districts and 17,156 live postcodes, from NN1 to NN29. It is centred on Northampton and also covers Corby, Wellingborough, Desborough, Daventry and Burton Latimer.
It is a dense area by postcode standards: an average of 903 postcodes per district,.
Where the NN districts sit
4 districts are plotted without a label where labels would overlap; every one is in the table below.
Where NN sits
It is administratively fragmented, reaching into North Northamptonshire, West Northamptonshire, Warwickshire and Bedford and 2 other authorities.
Water supply across NN
All 19 NN districts are supplied by Anglian Water. That makes NN simple in a way many areas are not: one company, one set of rules, one status to check.
Anglian Water has a hosepipe ban in force from 11 July 2026, covering the whole of NN.
The shape of the NN area
NN3 is the largest district with 1,315 postcodes around Northampton, and NN29 the smallest with 280. The area divides into 95 postcode sectors.
The numbering is not continuous. NN runs up to 29 but has only 19 districts, so 10 numbers are unused:.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: NN1, NN2, NN3, NN4, NN5, NN6 and NN7 all point at Northampton, NN8 and NN29 all point at Wellingborough and NN17 and NN18 all point at Corby.
What borders NN
NN sits next to MK (Bletchley) to the south east, CV (Coventry) to the west, LE (Leicester) to the north, LU (Luton) to the south east and OX (Oxford) to the south west.
Its neighbours run in 4 different directions, so NN is landlocked by other postcode areas on most sides.
NN districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| NN1 | Northampton | Anglian Water / Severn Trent | Depends on your supplier |
| NN2 | Northampton | Anglian Water / Severn Trent | Depends on your supplier |
| NN3 | Northampton | Anglian Water / Severn Trent | Depends on your supplier |
| NN4 | Northampton | Anglian Water / Severn Trent | Depends on your supplier |
| NN5 | Northampton | Anglian Water / Severn Trent | Depends on your supplier |
| NN6 | Northampton | Anglian Water / Severn Trent | Depends on your supplier |
| NN7 | Northampton | Anglian Water / Severn Trent | Depends on your supplier |
| NN8 | Wellingborough | Anglian Water / Severn Trent | Depends on your supplier |
| NN9 | Raunds | Anglian Water / Severn Trent | Depends on your supplier |
| NN10 | Rushden | Anglian Water / Severn Trent | Depends on your supplier |
| NN11 | Daventry | Anglian Water / Severn Trent | Depends on your supplier |
| NN12 | Towcester | Anglian Water / Severn Trent | Depends on your supplier |
| NN13 | Brackley | Anglian Water / Severn Trent | Depends on your supplier |
| NN14 | Desborough | Anglian Water / Severn Trent | Depends on your supplier |
| NN15 | Burton Latimer | Anglian Water / Severn Trent | Depends on your supplier |
| NN16 | Kettering | Anglian Water / Severn Trent | Depends on your supplier |
| NN17 | Corby | Anglian Water / Severn Trent | Depends on your supplier |
| NN18 | Corby | Anglian Water / Severn Trent | Depends on your supplier |
| NN29 | Wellingborough | Anglian Water / Severn Trent | Depends on your supplier |
Principal settlement is the town or city each district sits in or nearest to, derived from OS Open Names. It is not the Royal Mail post town, which is licensed data and not published openly. Status is resolved live from each company’s own notice.
Water hardness in NN
No water company covering NN publishes hardness figures as open data. The gap is named per district below so you know who to ask.
| District | Hardness | As published | Supply zone | Published by |
|---|---|---|---|---|
| NN1 | Not published by Anglian Water. Check with your supplier. | |||
| NN2 | Not published by Anglian Water. Check with your supplier. | |||
| NN3 | Not published by Anglian Water. Check with your supplier. | |||
| NN4 | Not published by Anglian Water. Check with your supplier. | |||
| NN5 | Not published by Anglian Water. Check with your supplier. | |||
| NN6 | Not published by Anglian Water. Check with your supplier. | |||
| NN7 | Not published by Anglian Water. Check with your supplier. | |||
| NN8 | Not published by Anglian Water. Check with your supplier. | |||
| NN9 | Not published by Anglian Water. Check with your supplier. | |||
| NN10 | Not published by Anglian Water. Check with your supplier. | |||
| NN11 | Not published by Anglian Water. Check with your supplier. | |||
| NN12 | Not published by Anglian Water. Check with your supplier. | |||
| NN13 | Not published by Anglian Water. Check with your supplier. | |||
| NN14 | Not published by Anglian Water. Check with your supplier. | |||
| NN15 | Not published by Anglian Water. Check with your supplier. | |||
| NN16 | Not published by Anglian Water. Check with your supplier. | |||
| NN17 | Not published by Anglian Water. Check with your supplier. | |||
| NN18 | Not published by Anglian Water. Check with your supplier. | |||
| NN29 | Not published by Anglian Water. Check with your supplier. | |||
Hardness is published per census area, not per postcode, so these figures characterise a district rather than measuring one address. They are a scale and taste matter, not a safety one. Hardness data version wessex-water@2022-2025+yorkshire-water@2026.
Download the NN data
No signup, no email wall. GeoJSON carries the district points, the supplier and the live status, so it can be dropped straight into a map.
District positions are averaged postcode centroids from OS Code-Point Open. They show roughly where a district sits, not where its boundary runs, and are not legal boundaries.
Frequently asked questions
How many postcode districts are in the NN area?
There are 19 NN postcode districts, running from NN1 to NN29, and they contain 17,156 live postcodes across 95 sectors.
What towns does the NN postcode area cover?
NN covers Northampton, Corby, Wellingborough, Desborough, Daventry and Burton Latimer. The area takes its name from Northampton, and each district is listed with its settlement in the table on this page.
Which water company supplies NN postcodes?
Anglian Water supplies all 19 NN districts. Supply boundaries follow the pipe network rather than postcode geography, so confirm against your water bill if you are near the edge of the area.
Why do NN1 and NN2 both say Northampton?
NN1, NN2, NN3, NN4, NN5, NN6 and NN7 all serve Northampton, covering different parts of it. A single town routinely needs more than one postcode district once it passes a few thousand delivery points, so this is normal rather than an error in an address.
Can I download a free NN postcode map?
Yes. This page offers the NN districts as GeoJSON, CSV and SVG, free and with no signup or email address required. The GeoJSON carries each district's position, its water company and its current restriction status, so it can be dropped straight into a mapping tool.
Which councils cover the NN postcode area?
NN reaches into North Northamptonshire, West Northamptonshire, Warwickshire, Bedford, Oxfordshire and Buckinghamshire. A postcode area is not a council area: they were drawn for different purposes and a single district can sit across a council boundary, so your postcode does not tell you which authority you pay.
Why is there no NN28 postcode district?
NN28 is not in use. Postcode districts are allocated as sorting requirements change rather than numbered straight through, and a code that is retired or never brought into service is not reissued, so gaps in the sequence are normal.