HP3 postcode district

Postcodes and sectors

763 of the district's 1,021 postcodes are live in the ONS Postcode Directory of August 2026. A postcode directory says whether a code is in use, never who is there. The live postcodes centre on 51.73565, -0.47168, which locates the district, not a building.

Companies registered in HP3

Companies House lists 2,195 companies with a registered office in HP3; 206 of them at addresses shared by 25 or more companies (1 October 2026 snapshot). 25 is the count at which the address lookup reports a company cluster.

Places OS Open Names lists for HP3

• Hertfordshire
• Eastern
• Dacorum
• Hemel Hempstead
• Bovingdon
• Three Rivers
• Pimlico
• Hogpits Bottom
• Flaunden
• Bulstrode
• St. Albans
• Rucklers Lane

Roads filed under HP3

Named roads first, then numbered ones. A road is filed under one district even where it runs through several, so a street missing here may be listed under a neighbouring district — which is why the address lookup never calls a British street absent. Great Britain has no open register of buildings, so a listed road never means a building on it exists.

• Acorn Road
• Alldicks Road
• Anelle Rise
• Anson Close
• Anvil Close
• Apple Cottages
• Apsley Grange
• Arden Close
• Arran Close
• Ash Grove
• Ashley Close
• Ashmore Gardens
• Ashridge Close
• Aston Close
• Athelstan Mews
• Athelstan Road
• Austins Mead
• Autumn Glades
• Avia Close
• Avocet Road
• Bailey Drive
• Balfour Mews
• Barnacres Road
• Barnard Way
• Barn Close
• Barnfield
• Barra Close
• Bartel Close
• Bedmond Road
• Beechwood Park
• Bell Green
• Belmont Road
• Belsize Close
• Belsize Road
• Belswains Lane
• Bennetts End Close
• Bennetts End Road
• Bevan Close
• Birch Lane
• Bittern Close
• Black Ditch Lane
• Black Robins Lane
• Blackwater Lane
• Blytheswod
• Blytheswood
• Bond Close
• Box Lane
• Brickfield Avenue
• Brickmakers Lane
• Bridgeview Close
• Brindley Way
• Bulstrode Lane
• Bunkers Lane
• Bunting Close
• Burnet Close
• Bury Rise
• Bushfield Road
• Butterfly Crescent
• Candlefield Close
• Candlefield Road

Check an address in HP3

Check an address in HP3

The same road list through the API, from the outward code alone:

curl "https://spaw.co/api/v1/address/streets?country=GB&postal_code=HP3" \
  -H "Authorization: Bearer $SPAW_KEY"

Common questions about HP3

What does an HP3 postcode tell you?

That the address lies in the HP3 district of the HP (Hemel Hempstead) postcode area, and the place OS Open Names most often lists first for its postcodes is Hemel Hempstead. The district alone does not place a street: the inward half of the full postcode narrows the address to one of the district's 763 live postcodes.

Where the counts come from

• ons-postcode-directory · version 2026-08 · Contains ONS, OS and Royal Mail data © Crown copyright and database right 2026, Open Government Licence v3.0. Northern Ireland postcodes are excluded: their reuse needs a Land & Property Services licence.
• os-open-names · version 2026-11-01 · Contains OS data © Crown copyright and database right 2026, Open Government Licence v3.0.
• uk-companies-house · version 2026-10-01 · Companies House free company data product, Open Government Licence v3.0

What each figure means, and what a district page never says, is set out in Reading a British postcode district page; the glossary defines a postcode district, a postcode area, a postcode directory and a street register.

Data synced on 2026-11-01: the newest version among the datasets listed above.

Districts nearest HP3

• HP12.6 km
• WD43.4 km
• HP23.5 km
• WD55.2 km
• HP47.6 km
• WD257.9 km
• AL38.2 km
• WD248.6 km
• WD179.2 km
• AL29.5 km
• HP59.8 km
• WD39.9 km
• Every district
• How a British address is written
• Check any address

distance between the districts' centroids