| 5 | Funky Elephant | Mobile caterer | Three Rivers | WD3 |
| 5 | Get Set 4 Tennis Ace Cafe | Restaurant/Cafe/Canteen | Three Rivers | WD3 9SL |
| 4 | Golden House | Takeaway/sandwich shop | Three Rivers | WD3 5NJ |
| Awaiting | Good Mushroom Nutrition LTD | Distributors/Transporters | Three Rivers | WD3 9XS |
| 3 | Green Island Fish & Chip Shop | Takeaway/sandwich shop | Three Rivers | WD3 8HE |
| 4 | Greens Essentials | Retailers - other | Three Rivers | WD3 3LE |
| 5 | Greggs PLC | Other catering premises | Three Rivers | WD3 1AP |
| 5 | Grocer On The Green | Retailers - other | Three Rivers | WD3 3LE |
| 5 | HCL @ Arnett Hills JMI School | School/college/university | Three Rivers | WD3 4BT |
| 5 | HCL @ Little Green JMI School | School/college/university | Three Rivers | WD3 3NJ |
| 5 | HCL @ Malvern Way School & Nursery | School/college/university | Three Rivers | WD3 3QQ |
| 5 | HCL @ Maple Cross Junior School | School/college/university | Three Rivers | WD3 9SS |
| 5 | HCL @ Rickmansworth Park JMI School | School/college/university | Three Rivers | WD3 1HU |
| 5 | HCL @ Shepherd Primary School | School/college/university | Three Rivers | WD3 8JJ |
| 5 | HCL @ St Mary's C Of E Primary School | School/college/university | Three Rivers | WD3 1NY |
| 4 | HCL @ St Peter's School | School/college/university | Three Rivers | WD3 8HD |
| 5 | HCL @ Yorke Mead Primary School | School/college/university | Three Rivers | WD3 3PX |
| 5 | Hannah's Kitchen | Retailers - other | Three Rivers | WD3 |
| 5 | Hanola Bakery | Other catering premises | Three Rivers | WD3 |
| 5 | Harvester | Pub/bar/nightclub | Three Rivers | WD3 3RX |
| 5 | Hillside Pre-School | Hospitals/Childcare/Caring Premises | Three Rivers | WD3 5AS |
| 5 | Holland & Barrett | Retailers - other | Three Rivers | WD3 1AN |
| 5 | Hollands | Retailers - other | Three Rivers | WD3 1EE |
| 5 | Hug A Leaf | Retailers - other | Three Rivers | WD3 6BX |
| 5 | Iceland | Retailers - supermarkets/hypermarkets | Three Rivers | WD3 1AJ |
| 5 | Impact Food Group @ York House School | School/college/university | Three Rivers | WD3 4LW |
| Awaiting | Impact Food Group Trading As Dolce @Sarratt C Of E Primary S | School/college/university | Three Rivers | WD3 6AS |
| 5 | In The Mood For Food | Mobile caterer | Three Rivers | WD3 |
| 5 | India Rasoi | Restaurant/Cafe/Canteen | Three Rivers | WD3 5RB |
| 5 | J Cakes | Retailers - other | Three Rivers | WD3 |
| Awaiting | Junior Adventures Group @ Merchant Taylors Prep | Hospitals/Childcare/Caring Premises | Three Rivers | WD3 1LW |
| 2 | K B R | Takeaway/sandwich shop | Three Rivers | WD3 4DF |
| 5 | K2 Catering | Mobile caterer | Three Rivers | WD3 |
| 5 | KFC | Takeaway/sandwich shop | Three Rivers | WD3 7DW |
| 5 | KSV Business | Restaurant/Cafe/Canteen | Three Rivers | WD3 7BQ |
| 5 | Kat's Kitchen | Other catering premises | Three Rivers | WD3 |
| 5 | Katie's Station Cafe | Restaurant/Cafe/Canteen | Three Rivers | WD3 1QY |
| 5 | Kebab Centre | Takeaway/sandwich shop | Three Rivers | WD3 7BE |
| 5 | Kisu Personal Chef | Other catering premises | Three Rivers | WD3 |
| 5 | Lilys Vegan Cakes | Retailers - other | Three Rivers | WD3 |
| 5 | Little Hands Adventure Club | School/college/university | Three Rivers | WD3 8HD |
| 5 | Livtocook | Retailers - other | Three Rivers | WD3 |
| Awaiting | Locitas Empanadas | Mobile caterer | Three Rivers | WD3 |
| 5 | Londis Rickmansworth | Retailers - other | Three Rivers | WD3 7BG |
| 5 | Love Desserts | Mobile caterer | Three Rivers | WD3 8DS |
| 5 | Luna Italian Restaurant | Restaurant/Cafe/Canteen | Three Rivers | WD3 5BB |
| Exempt | Lunch Club @ Mill End Baptist Church | Restaurant/Cafe/Canteen | Three Rivers | WD3 7EL |
| 3 | MEXICA CHINESE BUFFET LTD | Restaurant/Cafe/Canteen | Three Rivers | WD3 1QP |
| Awaiting | MFG Greggs Rickmansworth | Other catering premises | Three Rivers | WD3 7BQ |
| 5 | Mackays Amusements | Mobile caterer | Three Rivers | WD3 |