| Aylin Super Cleaning Limited | Administrative & support | 2025 |
| Ayling Properties Ltd | Real estate | 2015 |
| Ayniyass Limited | Wholesale & retail | 2024 |
| AYS Logistics Ltd | Transport & logistics | 2026 |
| AYS System Solution Ltd | Information & communication | 2024 |
| Aythorpe Investments Ltd | Financial services | 2024 |
| Aythorpe Promotions Ltd | Arts & recreation | 2024 |
| Aythorpe Storage Ltd | Transport & logistics | 2022 |
| Ayus Entprise Limited | Public administration | 2024 |
| Ayyappa PVT Limited | Hospitality | 2024 |
| AZ Asset Finance Limited | Financial services | 2018 |
| AZ Films Inc Ltd | Professional & scientific | 2018 |
| AZ Fire Protection Ltd | Construction | 2023 |
| AZ Hospitality Partners Limited | Hospitality | 2025 |
| AZ Plumbing & Heating Northampton Ltd | Construction | 2023 |
| AZ Racing Limited | Wholesale & retail | 2018 |
| AZ Tiling Solutions Limited | Construction | 2023 |
| Azana Studios Ltd | Information & communication | 2023 |
| Azaq Properties Ltd | Real estate | 2017 |
| Azaria Ltd | Professional & scientific | 2004 |
| Azayman Ltd | Transport & logistics | 2026 |
| Azch Limited | Professional & scientific | 2026 |
| Azdc Ltd | Hospitality | 2016 |
| Azea Limited | Real estate | 2018 |
| Azetcon Ltd | Construction | 2020 |
| AZG Trans Ltd | Transport & logistics | 2023 |
| Azimex Fabrications Limited | Manufacturing | 1981 |
| Azimex Investments Limited | Extraterritorial | 2003 |
| Azimex Properties Limited | Real estate | 1984 |
| Azimex Ventures Limited | Construction | 2026 |
| Aziz's Properties Ltd | Real estate | 2023 |
| AZJ Healthcare Services Limited | Health & social care | 2006 |
| Azorion Ltd | Real estate | 2022 |
| AZR Management Service Ltd. | Administrative & support | 2019 |
| Aztec Composites Limited | Manufacturing | 1997 |
| Aztec Windows (Coventry) Limited | Construction | 1992 |
| Azure Plumbing & Heating Ltd | Construction | 2005 |
| Azure Smart Limited | Administrative & support | 2017 |
| B & B News Limited | Wholesale & retail | 2013 |
| B & E Construction Ltd | Construction | 2016 |
| B & E Contract Cleaning Ltd | Administrative & support | 2019 |
| B & F Trustees Limited | Professional & scientific | 2016 |
| B & N Blinds Ltd | Financial services | 2023 |
| B a C (Wellingborough) Holdings Limited | Manufacturing | 2020 |
| B a Outsourcing Limited | Extraterritorial | 2011 |
| B C Logistics (Kettering) Limited | Transport & logistics | 2019 |
| B D Agency and Design Limited | Other services | 2009 |
| B England Contract Services Limited | Construction | 2007 |
| B H a Trees Ltd | Agriculture & fishing | 2008 |
| B J Thomas Limited | Professional & scientific | 2009 |
| B Kola Investment Ltd | Real estate | 2025 |
| B Massey Limited | Construction | 2011 |
| B Mead Roofing Specialist Limited | Construction | 2016 |
| B Moniri Ltd | Real estate | 2026 |
| B Pelicans Limited | Health & social care | 2018 |
| B T Watts Properties Ltd | Households | 2020 |
| B!Smart Health Ltd | Administrative & support | 2023 |
| B&B (UK) Ltd | Wholesale & retail | 2011 |
| B&D Trading Services Limited | Wholesale & retail | 2023 |
| B&E Driving Ltd | Transport & logistics | 2025 |
| B&F Northampton Ltd | Wholesale & retail | 2023 |
| B&G Trans Ltd | Transport & logistics | 2017 |
| B&K Hairdresser Ltd | Other services | 2021 |
| B&L Development Limited | Real estate | 2016 |
| B&M Couriers Limited | Transport & logistics | 2018 |
| B&M Surface Systems UK Limited | Manufacturing | 2014 |
| B&W Technologies Ltd | Professional & scientific | 2021 |
| B-One Aesthetics Limited | Other services | 2024 |
| B-Rut Trans Ltd | Transport & logistics | 2017 |
| B-Stone Limited | Wholesale & retail | 2005 |
| B. & C. (Duston) Management Company Limited | Households | 1982 |
| B.A.G. Car Storage Limited | Transport & logistics | 2002 |
| B.B. GAS & Plumbing Ltd | Construction | 2020 |
| B.E. Design Consultancy Limited | Professional & scientific | 2017 |
| B.H. Electric Ltd | Construction | 2024 |
| B.H.L.Aerial Installations Limited | Information & communication | 1957 |
| B.L.Z.L. Ltd | Transport & logistics | 2007 |
| B.M.B. Removals Limited | Administrative & support | 2001 |
| B.N.K. & SON Limited | Wholesale & retail | 1997 |
| B.R.B. Estates Limited | Real estate | 1997 |
| B.Z Transport Ltd | Manufacturing | 2021 |
| B2 Creative Ltd | Professional & scientific | 2018 |
| B2B Chic House Ltd | Information & communication | 2024 |
| B333GETP Ltd | Manufacturing | 2026 |
| B53 Holdings Ltd | Arts & recreation | 2023 |
| B6 Capital Partners Limited | Financial services | 2024 |
| BA National Ltd | Education | 2023 |
| Baaz Money Exchange Ltd | Other services | 2018 |
| Bababaraka Ltd | Transport & logistics | 2019 |
| Babalae Ltd | Wholesale & retail | 2025 |
| Babama ASP Limited | Hospitality | 2018 |
| Babama Enterprise Limited | Hospitality | 2014 |
| Babama Venture Limited | Hospitality | 2018 |
| Babbittles Properties LLP | | 2016 |
| Babcam Support for Living Limited | Health & social care | 2013 |
| Babilon Limited | Construction | 2020 |
| Baboti Limited | Information & communication | 2012 |
| Babs & LEW Developments Ltd | Real estate | 2020 |
| Babs 365 Ltd | Administrative & support | 2022 |
| Baby Grow Ltd | Wholesale & retail | 2025 |