- Airscan - AL9 6NE
- Aqualona Products Ltd - AL9 6NE
- Ashley Wilde Group - AL9 7LD
- B P Mitchell - AL9 5RB
- Briary Energy - AL9 5HZ
- Business Designs - AL9 7RN
- Caffeine Ltd - AL9 7NP
- Enterprise Hertfordshire - AL9 5BL
- Frank Taylor & Associates - AL9 7QR
- G T Towing Ltd - AL9 5SD
- Hallett Silbermann Ltd - AL9 7HF
- HAZ International Ltd - AL9 5JN
- IGPA Services Ltd - AL9 7NT
- Isuzu Truck UK Ltd - AL9 5JN
- Jumbo - AL9 5NB
- Lush Heat Treatment Ltd - AL9 5JN
- Mollart Universal Joints - AL9 7JB
- O-Pro Mouth Guards - AL9 7JE
- Pexhurst Services Ltd - AL9 7JL
- Renz UK Ltd - AL9 5PQ
- S & B Commercials - AL9 7HN
- Shindengen UK Ltd - AL9 5ER
- Thomson Software Solutions - AL9 7DW
- Thorns Group - AL9 7HN
- Welwyn Garden Alarms Ltd - AL9 5NB
- Zenith Hygiene Group Plc - AL9 7JE