- St Albans AL1 AL2 AL3 AL4
- Harpenden AL5
- Hatfield AL9 AL10
- Hemel Hempstead HP1 HP2 HP3
- Watford WD17 WD18 WD19 WD23 WD24 WD25
- Potters Bar EN6
- Brookmans Park AL9
- London Colney AL2
- Borehamwood WD6
- Radlett WD7
- Wheathampstead AL4
- Stevenage SG1 SG2 SG3
- Hitchin SG4 SG5 SG6
- Kings Langley WD4
- Abbots Langley WD5
- Rickmansworth WD3
- Welwyn AL6 AL7 AL8
- Shenley WD7
- Barnet EN EN5
- Enfield EN1 EN2 EN3
- Chesunt EN8