| Aujla Medical Limited | Wholesale & retail | 2022 |
| Aura Cribz Ltd | Hospitality | 2026 |
| Aura Gadgets Ltd | Wholesale & retail | 2025 |
| Aura Grimsby Ltd | Other services | 2022 |
| Aurafeeds Ltd | Information & communication | 2026 |
| Aurora Puppet Theatre Ltd | Extraterritorial | 2023 |
| Auspec Technology Ltd | Wholesale & retail | 2022 |
| Austin Harley Investments Ltd | Real estate | 2018 |
| Austin Pearce Holdings Limited | Professional & scientific | 2026 |
| Austins Property Group Ltd | Real estate | 2018 |
| Auto B&M Ltd | Wholesale & retail | 2023 |
| Auto Garage Network Ltd | Information & communication | 2017 |
| Auto Mind AI Agents Limited | Information & communication | 2026 |
| Auto Stocking Limited | Extraterritorial | 2019 |
| Automotive Glass Couriers Ltd | Transport & logistics | 2024 |
| Autosport Loughborough Ltd | Wholesale & retail | 2025 |
| Autoteam Centru Limited | Wholesale & retail | 2022 |
| AV Assistance Ltd | Administrative & support | 2024 |
| AVA Collections Ltd | Wholesale & retail | 2021 |
| Avaa Pharma Consultancy Ltd | Professional & scientific | 2023 |
| Avano Limited | Financial services | 2014 |
| Avaril Ltd | Wholesale & retail | 2026 |
| Avas Associates Ltd | Real estate | 2024 |
| Avec Support Services Ltd | Health & social care | 2026 |
| Aveda Consulting Ltd | Professional & scientific | 2016 |
| Avenew Ltd | Real estate | 2019 |
| Averok Limited | Wholesale & retail | 2026 |
| Avignon Holdings Limited | Financial services | 2025 |
| AVM Aviation Management Solutions Limited | Professional & scientific | 2015 |
| Avocado Gems Ltd | Manufacturing | 2022 |
| Avooze Limited | Wholesale & retail | 2025 |
| Avvio Limited | Administrative & support | 2014 |
| AW & SON Construction Ltd | Construction | 2025 |
| AW International Investments Limited | Real estate | 2017 |
| Awake Holdings Ltd | Financial services | 2018 |
| Awake Research Limited | Professional & scientific | 2016 |
| Awaken by T Ltd | Financial services | 2024 |
| Aweld Fabrications Limited | Manufacturing | 2006 |
| AWR Fabrications Ltd | Manufacturing | 2011 |
| AX9 Ltd | Information & communication | 2018 |
| Axiom Dynamicz Ltd | Wholesale & retail | 2026 |
| Axiom Economics Ltd | Professional & scientific | 2022 |
| Axioma Limited | Financial services | 2011 |
| AYA Tea Ltd | Real estate | 2012 |
| Ayan MD Builders Ltd | Construction | 2021 |
| Azoom Inc. Ltd | Arts & recreation | 2023 |
| Azorro Ltd | Administrative & support | 2025 |
| Azpack Limited | Manufacturing | 1992 |
| Aztec Mechanical Engineering Ltd | Professional & scientific | 2019 |
| B & H Developers Ltd | Construction | 2023 |
| B & J Engineering Leicester Limited | Manufacturing | 2015 |
| B Corp Folkes Limited | Professional & scientific | 2024 |
| B J Kavaney Limited | Professional & scientific | 2019 |
| B Therapies Ltd | Other services | 2026 |
| B&B Photography Ltd | Professional & scientific | 2022 |
| B&C Painting & Decorating Limited | Construction | 2025 |
| B&S Transport Midlands Ltd | Transport & logistics | 2019 |
| B&W Lettings & Management Ltd | Real estate | 2020 |
| B-Buddies CIC | Education | 2021 |
| B-Fashion Limited | Wholesale & retail | 2014 |
| B.A. Professional Cleaning Service Ltd | Administrative & support | 2021 |
| B.H Brickwork East Midlands Ltd | Construction | 2023 |
| B.M Project Engineering Ltd | Professional & scientific | 2020 |
| B.M.K Cars Ltd | Wholesale & retail | 2022 |
| B.P. Running Limited | Arts & recreation | 2023 |
| B12 Info Limited | Information & communication | 2014 |
| B2 Electrical Leicester Ltd | Construction | 2025 |
| B32 Films Limited | Information & communication | 2026 |
| BA Property Developments Ltd | Real estate | 2021 |
| Ba-Ha Vegan Ltd | Hospitality | 2019 |
| Babcock Transformers Limited | Professional & scientific | 1943 |
| Babsco Limited | Financial services | 2014 |
| Baby Art Loughborough Ltd | Professional & scientific | 2024 |
| Babystyle UK Limited | Manufacturing | 1999 |
| Back on the High Street Limited | Real estate | 2018 |
| Backrow Developments Ltd | Professional & scientific | 2026 |
| Bade Newby Display Limited | Manufacturing | 2005 |
| Badger Associates Leicester Limited | Real estate | 2021 |
| Baelthazar Publications Ltd | Information & communication | 2025 |
| Bagform International Ltd | Manufacturing | 2022 |
| BAGS2COVER Ltd | Manufacturing | 2003 |
| Bahamas Invest Holding Limited | Financial services | 2021 |
| Bailey Cluskey Carpentry Ltd | Construction | 2026 |
| Bailey Grove Management Company Limited | Administrative & support | 2006 |
| Bailey Opex Ltd | Professional & scientific | 2025 |
| Bailey's Property Maintenance Limited | Households | 2016 |
| Bains Construction Midlands Ltd | Construction | 2024 |
| Bakers Bond Limited | Wholesale & retail | 2014 |
| Bale Insurance Brokers Limited | Financial services | 2000 |
| Ballard's GAS Services Ltd | Construction | 2021 |
| Ballu Holdings Ltd | Administrative & support | 2022 |
| BALLZ2U Ltd | Wholesale & retail | 2025 |
| Balshaw Limited | Administrative & support | 2025 |
| Bamboo Partnership Ltd | Education | 2020 |
| Bamboo Street Food Ltd | Hospitality | 2018 |
| Bancroft Automotive Services Limited | Professional & scientific | 2013 |
| Bandicoot Boutique Limited | Wholesale & retail | 2009 |
| Baneenzy Ltd | Wholesale & retail | 2025 |
| Bantam Newco Limited | Financial services | 2025 |
| Baps Homes Limited | Real estate | 2002 |