| New Holland Sheet Metal Co. Limited | Manufacturing | 1974 |
| New Space Property Solutions Ltd | Real estate | 2020 |
| NL Architectural Structures Limited | Manufacturing | 2024 |
| NMD Associates Ltd | Construction | 2021 |
| NO Morals Limited | Other services | 2017 |
| North Eastern Tyre & Exhausts Limited | Wholesale & retail | 1987 |
| Norwich Financial Ltd. | Real estate | 1988 |
| Novaview Ltd | Construction | 2024 |
| Ogle Models and Prototypes Limited | Manufacturing | 1978 |
| Oliver Shuttleworth Fine Art Limited | Arts & recreation | 2014 |
| Oncu Food UK Ltd | Wholesale & retail | 2024 |
| Orobian Limited | Information & communication | 2012 |
| Paramount Consulting Group Limited | Information & communication | 2021 |
| Parico Services Limited | Professional & scientific | 1982 |
| Paul Wolfenden & Associates Limited | Professional & scientific | 2010 |
| Peanuckle Enterprises Limited | Wholesale & retail | 1975 |
| Peerless Designs (Letchworth) Limited | Manufacturing | 2015 |
| Pitta Shack Ltd | Wholesale & retail | 2019 |
| Powells Events Limited | Hospitality | 2019 |
| Primett House Limited | Real estate | 2023 |
| Print 2 Logistics Limited | Manufacturing | 2009 |
| Profit and Boss Limited | Professional & scientific | 2018 |
| Propergo Ltd | Wholesale & retail | 2022 |
| Pure Roofing Services Ltd | Construction | 2022 |
| R P B Building and Roofing Contractors Limited | Construction | 2008 |
| Rasoi of Sandy Ltd | Hospitality | 2017 |
| RB Tree and Landscape Services Limited | Administrative & support | 2022 |
| Rbloye Properties Limited | Real estate | 2016 |
| Realspace Holdings Ltd | Real estate | 2025 |
| Rebil Ltd | Real estate | 2024 |
| Red Larks Property Limited | Real estate | 2024 |
| Redest Consultancy Ltd | Information & communication | 2020 |
| Relax Pro Ltd | Wholesale & retail | 2019 |
| Relton Associates Limited | Manufacturing | 2016 |
| Retail Solutions Consulting Ltd | Information & communication | 2015 |
| Rfidentikit Limited | Information & communication | 2016 |
| Rosemere Horticulture Ltd | Wholesale & retail | 2025 |
| Royston Trust Limited | Professional & scientific | 1934 |
| RPB Carter Limited | Extraterritorial | 2010 |
| Safety for Business (UK) Limited | Education | 2013 |
| Saint Amand Leisure Ltd | Other services | 2010 |
| Sarabex Properties Limited | Real estate | 2017 |
| SAS Technical Services Ltd | Professional & scientific | 2024 |
| Satchells Estate Agents Limited | Real estate | 2014 |
| Sims Property Limited | Real estate | 2018 |
| Smarter POS Limited | Wholesale & retail | 2026 |
| SMY Medical Services Ltd | Health & social care | 2026 |
| SNG Catering Ltd | Administrative & support | 2015 |
| Specialist Aviation Properties Limited | Financial services | 2024 |
| Spiralarm Consulting Limited | Information & communication | 2013 |
| Sports Massage Letchworth Ltd | Health & social care | 2026 |
| ST. Christopher School Guilds Limited | Education | 1996 |
| ST. Francis Court Management (NO.2) Limited | Households | 1991 |
| Steeldeck Group Management Ltd | Professional & scientific | 2025 |
| Steelkonic Limited | Manufacturing | 2026 |
| Stem Engineering Limited | Professional & scientific | 2022 |
| Stevenage OIL Company Limited | Wholesale & retail | 1975 |
| Student City Inn Limited | Hospitality | 2015 |
| Swiftware Ltd | Information & communication | 2015 |
| Syag Properties Ltd | Real estate | 2026 |
| Talk to a Peer Limited | Extraterritorial | 2025 |
| THE Artisan Cookery Limited | Hospitality | 2020 |
| THE Avenue Motion Picture Company Limited | Information & communication | 2014 |
| THE Chop Spot Ltd | Hospitality | 2018 |
| THE Creative Hearts CIC | Education | 2025 |
| THE Cuticle OIL Company Ltd | Wholesale & retail | 2021 |
| THE Essential Suppliers Limited | Wholesale & retail | 2010 |
| THE Fragrance House Group Limited | Manufacturing | 2011 |
| THE Hidden Barrel Ltd | Hospitality | 2025 |
| THE Norton Croft Management Company Limited | Households | 1988 |
| THE Profile People Ltd | Education | 2015 |
| THE Social Byrd Limited | Professional & scientific | 2025 |
| Tongues OUT Ltd | Other services | 2023 |
| Top HAT Stage and Screen School Limited | Arts & recreation | 2008 |
| Top Talent Agency Limited | Arts & recreation | 2008 |
| Trade & Retail Ltd | Wholesale & retail | 2019 |
| True Creations Ltd | Information & communication | 2024 |
| TT Installations Limited | Construction | 2017 |
| Tudoo Ltd | Information & communication | 2016 |
| Tulino Psychology and CBT Consultancy Ltd | Health & social care | 2018 |
| UK MSK Limited | Health & social care | 2013 |
| Uranus Trading Ltd | Wholesale & retail | 2014 |
| USA Chicken Letchworth Limited | Hospitality | 2026 |
| Vellaro Sports Ltd | Wholesale & retail | 2026 |
| Vision Services (Herts) Limited | Construction | 2004 |
| Waterhouse Residents Management Company Limited | Households | 2025 |
| West Oak Building Services Limited | Extraterritorial | 2002 |
| West Oak Joinery Limited | Construction | 1989 |
| Widetone Limited | Transport & logistics | 1993 |
| Wilbury (UK) Ltd | Real estate | 2014 |
| Williams Project Planning & Controls Ltd | Professional & scientific | 2019 |
| Wired Retail Group Ltd | Manufacturing | 2017 |
| YAL Holdings Ltd | Health & social care | 2022 |
| Yoga Team Limited | Health & social care | 2008 |
| Yolo by BIS Bousa Ltd | Education | 2023 |
| Zarif Ltd | Wholesale & retail | 2022 |
| Zentara Holdings Limited | Financial services | 2025 |
| Zentara International Limited | Manufacturing | 2025 |