Postcode district boundaries:
|Postcode area name|
|Statistics as at May 2020|
The AL postcode area, also known as the St Albans postcode area, is a group of ten postcode districts in England, within five post towns. These cover central Hertfordshire, including St Albans, Harpenden, Welwyn, Welwyn Garden City and Hatfield.
Mail for this area is processed at the Home Counties North Mail Centre in Hemel Hempstead, and is delivered from offices at St Albans (Brick Knoll Park AL1), Harpenden (Station Road AL5), and Hatfield (Town Centre AL10). The area covered includes most of the St Albans and Welwyn Hatfield districts, plus the northeastern part of the Dacorum district and very small parts of the Hertsmere, North Hertfordshire and East Hertfordshire districts.
The approximate coverage of the postcode districts:
|Postcode district||Post town||Coverage||Local authority area(s)|
|AL1||ST ALBANS||St Albans||St Albans|
|AL2||ST ALBANS||St Albans, Bricket Wood, Colney Street, Frogmore, London Colney, Napsbury, Park Street, Potters Crouch, Chiswell Green||St Albans, Hertsmere|
|AL3||ST ALBANS||St Albans, Childwickbury, Flamstead, Gorhambury, Markyate, New Greens, Porters Wood, Redbourn, Sandridge||St Albans, Dacorum|
|AL4||ST ALBANS||St Albans, Blackmore End, Colney Heath, London Colney, Jersey Farm, Marshalswick, Oaklands, Sandridge, Smallford, Tyttenhanger, Wheathampstead||St Albans, Hertsmere, North Hertfordshire|
|AL5||HARPENDEN||Harpenden, Kinsbourne Green||St Albans|
|AL6||WELWYN||Welwyn, Ayot St Peter, Ayot St Lawrence, Digswell, Rabley Heath, Tewin||Welwyn Hatfield, East Hertfordshire, North Hertfordshire|
|AL7||WELWYN GARDEN CITY||Welwyn Garden City (east)||Welwyn Hatfield|
|AL8||WELWYN GARDEN CITY||Welwyn Garden City (west), Lemsford||Welwyn Hatfield|
|AL9||HATFIELD||Hatfield (Old Hatfield), Brookmans Park, Essendon, North Mymms, Welham Green||Welwyn Hatfield|
|AL10||HATFIELD||Hatfield (new town)||Welwyn Hatfield|
- "ONS Postcode Directory Version Notes" (ZIP). National Statistics Postcode Products. Office for National Statistics. May 2020. Table 2. Retrieved 19 June 2020. Coordinates from mean of unit postcode points, "Code-Point Open". OS OpenData. Ordnance Survey. February 2012. Retrieved 21 April 2012.
- Royal Mail, Address Management Guide, (2004)