| Raise House Limited | Health & social care | 2016 |
| Red Beard Collections Ltd | Administrative & support | 2025 |
| Red Kite 9 Ltd | Information & communication | 2021 |
| Redvulette Ltd | Wholesale & retail | 2017 |
| Remote Audio Post Limited | Information & communication | 2020 |
| Rolla Granola Limited | Manufacturing | 2018 |
| SAB Procurement Solutions Limited | Professional & scientific | 2016 |
| Service Scan Evaluations Limited | Administrative & support | 1996 |
| Seymour Plumbing Ltd | Construction | 2018 |
| Simply Fireplaces Limited | Wholesale & retail | 2024 |
| Special Effects ETC Limited | Information & communication | 2020 |
| ST James Court Harpenden Freehold Company Ltd | Households | 2025 |
| Stevenage Wellbeing Ltd | Health & social care | 2024 |
| Sunflower Financial Services Limited | Financial services | 2022 |
| THE 19THOLE Limited | Information & communication | 2019 |
| THE Adventure Running Company Ltd | Administrative & support | 2017 |
| THE Barn Residents Association Limited | Real estate | 1990 |
| THE Executive Insight Collective Ltd | Other services | 2021 |
| THE Filmers Video Productions Ltd | Information & communication | 2017 |
| THE Mystery Shopping Company Limited | Extraterritorial | 2005 |
| THE Old Brewhouse Coffee Ltd | Manufacturing | 2020 |
| THE Tuckermoore Family Investment Company Limited | Financial services | 2019 |
| THE Z Squared Group Ltd | Professional & scientific | 2015 |
| Thomas Crouch Developments Limited | Construction | 2018 |
| Timbercombe QS Services Limited | Construction | 2019 |
| Toaster Creative Limited | Information & communication | 2018 |
| Trevose Estates Limited | Real estate | 2022 |
| Trimac Ltd | Real estate | 2023 |
| Two Viewbank Ltd | Professional & scientific | 2019 |
| Waddington on the Road Ltd | Hospitality | 2017 |
| WD Crow Ltd | Financial services | 2022 |
| Wheathampstead Well-Being Ltd. | Health & social care | 2019 |
| WIN That Pitch Limited | Professional & scientific | 2018 |
| Worksmart HR Limited | Professional & scientific | 2014 |
| Zeho Projects Ltd | Construction | 2017 |