| 007UNIVERSE Ltd | Administrative & support | 2017 |
| 11 the Watermark Ltd | Hospitality | 2023 |
| 13/15 Church Street Management Company Limited | Households | 1997 |
| 2OYAL Limited | Construction | 2015 |
| 360 Heating Ltd | Construction | 2014 |
| 360 Mechanical Ltd | Construction | 2022 |
| 3ALFA Group Ltd | Hospitality | 2021 |
| 44COLLECTION Ltd | Information & communication | 2023 |
| 4T1 Limited | Information & communication | 2016 |
| 51 High Street Langford Freehold Limited | Real estate | 2016 |
| 7STORM Media Brit Ltd | Information & communication | 2019 |
| A & M Manufacturing Company Ltd | Wholesale & retail | 2014 |
| A.T Maile Limited | Professional & scientific | 2019 |
| A1 Airworks Limited | Wholesale & retail | 1998 |
| A1 Trade Marks Limited | Professional & scientific | 2018 |
| AA UK Property Management Ltd | Real estate | 2026 |
| AAA Property Management Services Ltd | Administrative & support | 2017 |
| AAP Dwellings Ltd | Construction | 2020 |
| Ability Squared Limited | Administrative & support | 2018 |
| Abrook Development Limited | Administrative & support | 2014 |
| ACC Pattison Limited | Construction | 2017 |
| Ace LOG Ltd | Transport & logistics | 2024 |
| Aced Assets Ltd | Real estate | 2022 |
| Aced Developments Ltd | Real estate | 2013 |
| ACJ Electrical Ltd | Construction | 2016 |
| ACO Tech Services Ltd | Information & communication | 2026 |
| ACR Traffic Management Ltd | Construction | 2023 |
| AD Networks Limited | Information & communication | 2002 |
| Adae Ltd | Construction | 2021 |
| Admiral Rentals Limited | Real estate | 2016 |
| Adrit Limited | Health & social care | 2018 |
| AEB Media Ltd | Professional & scientific | 2021 |
| Aesthetics by Jacqueline Ltd | Other services | 2025 |
| AGF UK Enterprises Ltd | Extraterritorial | 2024 |
| AH Group Limited | Financial services | 2021 |
| AH Management Services Limited | Real estate | 2021 |
| AH Support Services Limited | Construction | 2005 |
| Akta Top Ltd | Construction | 2017 |
| Alam Consulting Limited | Professional & scientific | 2019 |
| Albury FUN Ltd | Hospitality | 2024 |
| ALF Consulting Limited | Administrative & support | 2023 |
| Altamira Training Ltd. | Education | 2013 |
| AM Carpentry & Building Welwyn Ltd | Construction | 2015 |
| Amir Interior Solutions Ltd | Construction | 2002 |
| AMK2 Real Estate Limited | Real estate | 2017 |
| Amplifi Africa Limited | Professional & scientific | 2026 |
| Anderson Accountancy Limited | Professional & scientific | 2000 |
| Andrew Holden Advisory Ltd | Professional & scientific | 2024 |
| Angel Films (London) Limited | Administrative & support | 2008 |
| Antler Consultancy Limited | Professional & scientific | 2025 |
| Appin Properties Ltd | Real estate | 2021 |
| Applymedia Limited | Professional & scientific | 1996 |
| APV Investments Limited | Real estate | 2020 |
| Aquaspark Contractors Limited | Construction | 2015 |
| ARC 4 Consulting Limited | Professional & scientific | 2025 |
| Archibald Investigations Limited | Administrative & support | 2015 |
| Argento Design Studio Ltd | Professional & scientific | 2008 |
| Armstrong Studio Ltd | Professional & scientific | 2018 |
| Arraysoft Ltd | Information & communication | 2021 |
| Arsenal Search Limited | Information & communication | 2022 |
| Asbury Business Consultancy Ltd | Professional & scientific | 2016 |
| Asil Nonreg Limited | Financial services | 2017 |
| ASK Brenda Ltd | Education | 2012 |
| Assemble UK Limited | Construction | 2009 |
| AT Design (Welwyn) Ltd | Professional & scientific | 2011 |
| Atal Management Limited | Professional & scientific | 2022 |
| Atlas Landscaping Supplies Ltd | Manufacturing | 2023 |
| Audio Visual Facilities Limited | Construction | 2000 |
| Aura IT Limited | Information & communication | 2007 |
| Aura Leisure Ltd | Information & communication | 2004 |
| Austen COX Vehicle Refinishing Ltd | Wholesale & retail | 2016 |
| Austin Creative Consultancy Ltd | Information & communication | 2024 |
| Autoideal UK Ltd | Information & communication | 2026 |
| Avey of London Limited | Professional & scientific | 2016 |
| Awesome Limited | Information & communication | 2000 |
| Awoi Ltd | Professional & scientific | 2026 |
| Ayot House Residents Limited | Households | 1978 |
| B-Hive Properties Central Ltd | Real estate | 2014 |
| Babatoto & Co Ltd | Wholesale & retail | 2025 |
| BAD Boys Garage Ltd | Manufacturing | 2019 |
| Bagels & Beyond Limited | Hospitality | 2025 |
| Balance Consultation Limited | Professional & scientific | 2024 |
| Ball & Brothers Limited | Construction | 2002 |
| Barwood Consultancy Limited | Administrative & support | 2017 |
| Baseline Complete Construction Limited | Construction | 2003 |
| Baseline Electrical Limited | Professional & scientific | 2003 |
| Baseline Portfolio Limited | Professional & scientific | 2003 |
| Baseline Property Development Limited | Real estate | 2003 |
| Baseline Property Managemant Letting Limited | Professional & scientific | 2003 |
| Basetime Solutions Limited | Professional & scientific | 2021 |
| Bben Estates Limited | Real estate | 1988 |
| Beactive Clinic Limited | Health & social care | 2016 |
| Becks Electrical & Building Services Limited | Construction | 2017 |
| Becky Nathan Hairdressing Ltd | Other services | 2020 |
| Bedfordshire Shoulder & Elbow Surgery Ltd | Health & social care | 2025 |
| Bella Therapie Ltd | Wholesale & retail | 2020 |
| Beresford Interim Management Limited | Information & communication | 2016 |
| Best Bohemia Engineering Ltd. | Manufacturing | 2019 |
| BGH Investments Ltd | Financial services | 2020 |
| BH Analytics Limited | Professional & scientific | 2020 |