| 0121 Television Limited | Information & communication | 2020 |
| 1415 Motorsports (UK) Limited | Arts & recreation | 2014 |
| 2 Church Ltd | Real estate | 2018 |
| 291/305 Church Road Residents Management Limited | Households | 1967 |
| 34 Lower Addison Gardens Limited | Real estate | 1989 |
| 715 Trading Ltd | Wholesale & retail | 2020 |
| A & E Smart Solutions Ltd | Wholesale & retail | 2012 |
| A & E Vehicle Services Ltd | Wholesale & retail | 2011 |
| A Golfing Experience Limited | Administrative & support | 2009 |
| A&Y Consulting Ltd | Professional & scientific | 2024 |
| A2B4P Limited | Professional & scientific | 2013 |
| AA Risk Advisory Ltd | Professional & scientific | 2026 |
| ABI Technology Limited | Information & communication | 2017 |
| Abstract Hoarding and Encapsulations Ltd | Construction | 2015 |
| Accura Properties Limited | Construction | 2020 |
| Aces Models Ltd | Professional & scientific | 2025 |
| Acorn 81 Property Ltd | Real estate | 2021 |
| Acorn Kennels & Cattery Ltd | Agriculture & fishing | 2017 |
| ADR Valeting Ltd | Other services | 2022 |
| AF Media Solutions Ltd | Professional & scientific | 2024 |
| AFA 20 Ltd | Health & social care | 2020 |
| AHS Interiors Ltd | Construction | 2021 |
| AIM High Properties Ltd | Extraterritorial | 2023 |
| AJC Legal Consultants Limited | Professional & scientific | 2023 |
| AJP Projects Ltd | Professional & scientific | 2025 |
| Alan Day Investments LLP | | 2010 |
| Alex Gray Ltd | Professional & scientific | 2026 |
| Alexander & Co. (Accountancy) Limited | Professional & scientific | 2003 |
| Alkaline Limited | Hospitality | 2018 |
| ALL Location Crew Services Limited | Information & communication | 2018 |
| Alma Artists Limited | Administrative & support | 2018 |
| Almendros Managed Services Ltd | Construction | 2026 |
| Alpha Quant Systems Ltd | Information & communication | 2024 |
| Alpine Excalibur Refrigeration Ltd | Manufacturing | 2026 |
| Ambice Group Ltd | Professional & scientific | 2024 |
| Amuahlets Limited | Real estate | 2026 |
| Anthony Marsland Limited | Financial services | 2007 |
| Any-Spec Cars Limited | Wholesale & retail | 2014 |
| Apricus HR Consultancy Limited | Administrative & support | 2024 |
| Arlington Supplies Ltd | Wholesale & retail | 2023 |
| Artemis Legal Services Limited | Professional & scientific | 2012 |
| Artform Landscapes Limited | Administrative & support | 2021 |
| Artpad Ltd | Professional & scientific | 2018 |
| Asian Fusion Kitchen Limited | Hospitality | 2022 |
| Astro Electrical Limited | Construction | 2024 |
| Atelier HR Limited | Administrative & support | 2022 |
| Baker Accountancy Services Ltd | Professional & scientific | 2026 |
| Bambino Developments Limited | Construction | 1971 |
| Barlow Consultancy Services Ltd | Real estate | 2022 |
| Barnes Electrical Contractors Limited | Construction | 2005 |
| Barra Films Limited | Information & communication | 2003 |
| Beef & Leaf Limited | Hospitality | 2025 |
| Benjamin Tyler Limited | Administrative & support | 2023 |
| Bentall Ventures Ltd | Real estate | 2022 |
| Better Mind Coaching Ltd | Education | 2026 |
| Beyond Finance Ltd | Financial services | 1997 |
| Biogemini Limited | Professional & scientific | 2002 |
| Bishop Salons Limited | Other services | 2025 |
| Bitethehand Creative Limited | Information & communication | 2008 |
| Blamf Associates Ltd | Construction | 2017 |
| Blest Supplies Ltd | Wholesale & retail | 2024 |
| Blue Carbon Ltd | Wholesale & retail | 2018 |
| Bluepath Limited | Professional & scientific | 2002 |
| Boosthq Ltd | Professional & scientific | 2019 |
| Bowker Construction Limited | Construction | 2016 |
| Buckley's Heating Ltd | Construction | 2018 |
| BY Teachers for Teachers Ltd | Education | 2020 |
| Calforce Limited | Real estate | 2005 |
| Careerskitchen Ltd | Professional & scientific | 2020 |
| Caroline Worboys Consulting Limited | Professional & scientific | 2015 |
| Carrington Stevens Restaurants Limited | Other services | 1989 |
| Casino Brokers Limited | Professional & scientific | 2017 |
| Casino Compliance Ltd | Professional & scientific | 2011 |
| Castle Building Projects Limited | Other services | 2018 |
| Castle Gate Installations Ltd | Construction | 2009 |
| Catabase Consulting Limited | Administrative & support | 2012 |
| Catnap Creations Ltd | Administrative & support | 2014 |
| Cayron Limited | Professional & scientific | 2021 |
| CEK Properties Limited | Real estate | 2021 |
| Chalfont Discount Tyres Ltd | Wholesale & retail | 2024 |
| Chalfont Wasps Football Club Ltd | Arts & recreation | 2022 |
| Changing Communication Ltd | Professional & scientific | 2019 |
| CHARCROSS21 Ltd | Construction | 2017 |
| Chef MAX Ltd | Hospitality | 2019 |
| Chiltern Building & Property Maintenance Limited | Construction | 2019 |
| Chiltern Concepts Limited | Construction | 2023 |
| Chiltern Estates Limited | Real estate | 2017 |
| Churchills Law Limited | Professional & scientific | 2014 |
| CKH Capital Ltd | Real estate | 2026 |
| CL Number Twenty Limited | Real estate | 2016 |
| Clayhall Estates Limited | Real estate | 1932 |
| Cleare Place Management Company Limited | Households | 2004 |
| Clearview Residential (Mount Grace) Limited | Construction | 2019 |
| Clifton Environmental Services Limited | Professional & scientific | 1998 |
| Climb Hitchin CIC | Arts & recreation | 2023 |
| Cmlk Limited | Construction | 2024 |
| Coleman Joinery Limited | Construction | 2022 |
| Colv & Co Ltd | Real estate | 2019 |
| Complete Aviation Ltd | Information & communication | 2020 |
| Concert by the Castle Limited | Arts & recreation | 2023 |