| 5 | Canopy Potters Bar | School/college/university | Hertsmere | EN6 5DB |
| 5 | Caretech Com Services | Hospitals/Childcare/Caring Premises | Hertsmere | EN6 2BZ |
| 5 | Carl's Burgers | Mobile caterer | Hertsmere | - |
| 5 | Carolina's Sweets | Other catering premises | Hertsmere | WD23 |
| 5 | Cask And Stillage | Pub/bar/nightclub | Hertsmere | EN6 5AJ |
| 5 | Cate's Grill | Mobile caterer | Hertsmere | WD6 |
| 5 | Catering By Penny Beral | Other catering premises | Hertsmere | WD7 |
| 5 | Catering By Tracey Spalter | Other catering premises | Hertsmere | WD23 |
| 5 | Caterplus @ McCarthy & Stone - Mandeville Court | Hospitals/Childcare/Caring Premises | Hertsmere | - |
| 5 | Caterplus @ McCarthy & Stone Goldwyn House | Hospitals/Childcare/Caring Premises | Hertsmere | - |
| 5 | Caterplus @ Rosary Priory | Hospitals/Childcare/Caring Premises | Hertsmere | WD23 4EE |
| 5 | Chatter Table | Restaurant/Cafe/Canteen | Hertsmere | WD6 5EQ |
| 5 | Cheat Meals | Takeaway/sandwich shop | Hertsmere | WD6 1DR |
| 5 | Cheeky Monkeys | Hospitals/Childcare/Caring Premises | Hertsmere | WD6 1JU |
| 5 | Chikayan Chinese Restaurant | Restaurant/Cafe/Canteen | Hertsmere | WD23 1EE |
| 3 | Chilli N Spice | Takeaway/sandwich shop | Hertsmere | EN6 5BB |
| 4 | Chimney Cake House | Mobile caterer | Hertsmere | - |
| 4 | China Style | Takeaway/sandwich shop | Hertsmere | EN6 2QS |
| 5 | Chloe's Cakeaway | Other catering premises | Hertsmere | EN6 |
| Awaiting | Clear Aesthetics By KP | Retailers - other | Hertsmere | WD6 |
| 5 | Clock Tower Mews (Caretech Ltd) | Hospitals/Childcare/Caring Premises | Hertsmere | EN6 5HA |
| 5 | Clockhouse Cafe | Restaurant/Cafe/Canteen | Hertsmere | WD6 3BD |
| 5 | Clore Shalom School | School/college/university | Hertsmere | WD7 9BL |
| 5 | Cloud Chasers | Retailers - other | Hertsmere | WD23 1BD |
| 5 | Co-Op | Retailers - supermarkets/hypermarkets | Hertsmere | EN6 5AS |
| Exempt | Co-Op | Retailers - supermarkets/hypermarkets | Hertsmere | WD6 4EB |
| 5 | Co-Operative Group (CWS) Limited | Retailers - supermarkets/hypermarkets | Hertsmere | WD6 4TH |
| 5 | Cobbs Bakery Sandwich Bar | Takeaway/sandwich shop | Hertsmere | EN6 5AB |
| Pending | Coopers Croft Care Home | Hospitals/Childcare/Caring Premises | Hertsmere | EN6 4AE |
| 4 | Costa Coffee | Restaurant/Cafe/Canteen | Hertsmere | EN6 1BJ |
| 5 | Costa Coffee | Restaurant/Cafe/Canteen | Hertsmere | WD6 4PR |
| 5 | Costa Coffee | Restaurant/Cafe/Canteen | Hertsmere | EN6 2PB |
| 5 | Costa Ltd | Restaurant/Cafe/Canteen | Hertsmere | WD6 1JG |
| 5 | Costco Europe (UK) Ltd (Deli, Butchery, Bakery, Warehouse, F | Restaurant/Cafe/Canteen | Hertsmere | WD25 8JS |
| 4 | Costcutter | Retailers - other | Hertsmere | WD6 2NY |
| 5 | Cowley Hill School | School/college/university | Hertsmere | WD6 5DP |
| 5 | Cranborne Convienence Store & Post Office | Retailers - other | Hertsmere | EN6 3BA |
| 5 | Cranborne Primary School | School/college/university | Hertsmere | EN6 2BA |
| 5 | Creams Dessert Cafe | Restaurant/Cafe/Canteen | Hertsmere | WD6 1AH |
| 5 | Creative Catering | Other catering premises | Hertsmere | EN6 |
| 5 | Crumbelievable Bakery | Other catering premises | Hertsmere | WD23 |
| Exempt | Crystal Salt Cave | Retailers - other | Hertsmere | WD6 1AG |
| 5 | Cucina At The Grange Academy | School/college/university | Hertsmere | WD23 3AA |
| 5 | Cuffley Manor Care Home | Hospitals/Childcare/Caring Premises | Hertsmere | EN6 4AA |
| 5 | Culinera @ Dame Alice Owens School | School/college/university | Hertsmere | EN6 2DU |
| 5 | Culinera At Hertswood Academy | Hospitals/Childcare/Caring Premises | Hertsmere | WD6 5LG |
| 5 | Culinera At Queens School North And South | School/college/university | Hertsmere | WD23 2TY |
| 5 | Curri.Co.UK | Takeaway/sandwich shop | Hertsmere | WD6 4LA |
| 4 | DAS Store | Retailers - other | Hertsmere | WD23 2LX |
| 4 | DHABA7 London | Other catering premises | Hertsmere | WD6 |