| AWE Pension Trustees Limited | Administrative & support | 1993 |
| AWE PLC | Manufacturing | 1992 |
| Awesome Technology Giant Ltd | Information & communication | 2011 |
| AWJ Group Ltd | Professional & scientific | 2022 |
| AWK Property Ltd | Real estate | 2019 |
| AWM Roofing & Building Limited | Construction | 2023 |
| Awrah Clothing Ltd | Wholesale & retail | 2021 |
| AWS & Adam Motors Ltd | Wholesale & retail | 2025 |
| AWT Energy Consulting Ltd | Professional & scientific | 2013 |
| Awtech Solutions Ltd | Information & communication | 2021 |
| AX Brickwork Limited | Construction | 2018 |
| AXE Business Colab Limited | Administrative & support | 2025 |
| Axenor Corporation Ltd | Administrative & support | 2026 |
| AXG Lighting Technology Limited | Wholesale & retail | 2016 |
| Axial Cargo Line Ltd | Transport & logistics | 2018 |
| Axial.Ai Ltd | Information & communication | 2022 |
| Axino Ltd | Administrative & support | 2016 |
| Axiom Two Limited | Information & communication | 2014 |
| Axis Clean Group Ltd | Administrative & support | 2025 |
| Axis IT Consulting Ltd | Information & communication | 2012 |
| Axis Resource Centre Limited | Health & social care | 2021 |
| Axis Resource Solutions Ltd | Health & social care | 2022 |
| Axis Spine Technologies Ltd | Professional & scientific | 2016 |
| Axis World Limited | Information & communication | 2026 |
| AXLE4 Motor Company Limited | Wholesale & retail | 2023 |
| Axolotl Futures Ltd | Arts & recreation | 2025 |
| Axolt Ltd | Information & communication | 2009 |
| Axon Global Consultancy Ltd | Information & communication | 2023 |
| AXR Homes Ltd | Real estate | 2020 |
| Axunio Ltd | Wholesale & retail | 2024 |
| Ayan Group Limited | Hospitality | 2020 |
| Ayanova Enterprise Ltd | Information & communication | 2024 |
| Ayatipharma Limited | Health & social care | 2025 |
| Ayaton Properties Limited | Real estate | 2021 |
| Ayhaan Ltd | Real estate | 2023 |
| Aylin Solutions Limited | Information & communication | 2026 |
| Aymanservices Ltd | Transport & logistics | 2022 |
| Ayne Advisors Limited | Professional & scientific | 2022 |
| Aynet Property Solutions Ltd | Real estate | 2021 |
| Aynet Solutions Ltd | Information & communication | 2017 |
| Aypcuk Limited | Other services | 2022 |
| AYS Autos and Tyre Centre Ltd | Wholesale & retail | 2024 |
| AYS Business Moves Limited | Transport & logistics | 2000 |
| AYS Removals and Storage Limited | Transport & logistics | 2016 |
| Aytonian Limited | Professional & scientific | 2015 |
| Ayub Butt Services Ltd | Information & communication | 2013 |
| Ayus Health Ltd | Professional & scientific | 2026 |
| AYW Management Limited | Information & communication | 2022 |
| AZ Cyber Insight Ltd | Information & communication | 2022 |
| AZ Data Communications Limited | Information & communication | 2024 |
| AZ Smart Shop Ltd | Wholesale & retail | 2019 |
| Azaca Ltd | Information & communication | 2026 |
| Azari Collection Limited | Wholesale & retail | 2024 |
| Azbeautyuk Ltd | Other services | 2024 |
| Azcr Limited | Agriculture & fishing | 2026 |
| Azeeko Limited | Professional & scientific | 2024 |
| Azego Group Holdings Limited | Financial services | 2022 |
| Azego TS Limited | Information & communication | 1996 |
| Azhar Consulting Group Ltd | Information & communication | 2026 |
| Azif Limited | Wholesale & retail | 2026 |
| Aziro Technologies UK Ltd | Information & communication | 2026 |
| AZS Contractors Ltd | Construction | 2023 |
| AZS Services Ltd | Construction | 2023 |
| Aztec Complete Services (Holdings) Limited | Administrative & support | 2014 |
| Aztech Services Limited | Information & communication | 2023 |
| Azton-Tech Ltd | Information & communication | 2024 |
| Azura Partners Ltd | Financial services | 2018 |
| Azurus Solutions Limited | Administrative & support | 2007 |
| Azwoodworks Ltd | Manufacturing | 2025 |
| B & a Interiors Limited | Construction | 2012 |
| B & B Local Limited | Wholesale & retail | 2017 |
| B Crew Limited | Administrative & support | 2010 |
| B Duckett Trading Limited | Professional & scientific | 2023 |
| B K a (UK) Limited | Information & communication | 1998 |
| B K Design Development Limited | Professional & scientific | 2016 |
| B N Beauty Ltd | Other services | 2017 |
| B S Infotek Limited | Information & communication | 2010 |
| B S W Engineering (U.K.) Limited | Manufacturing | 2000 |
| B Sealey Construction Ltd | Construction | 2022 |
| B Sillah Global Ltd | Wholesale & retail | 2026 |
| B W Datacoms Limited | Information & communication | 2018 |
| B W P Property Limited | Real estate | 2003 |
| B Wholesales and Co Limited | Wholesale & retail | 2019 |
| B&B Family Limited | Hospitality | 2019 |
| B&B Shopfittings Limited | Wholesale & retail | 2000 |
| B&D Builders Ltd | Construction | 2025 |
| B&G Gardening Ltd | Administrative & support | 2025 |
| B&H Builds Ltd | Construction | 2026 |
| B&O Logistic Limited | Transport & logistics | 2025 |
| B&P Maintenance Limited | Construction | 2020 |
| B&R Exterior Cleaning Services Ltd | Administrative & support | 2025 |
| B&R Plumbing and Heating Services Limited | Construction | 1998 |
| B&S Food and Wine Ltd | Wholesale & retail | 2024 |
| B&S Management Ltd | Real estate | 2024 |
| B&Sb Services Ltd | Health & social care | 2025 |
| B&W Fuels Ltd | Wholesale & retail | 2021 |
| B-Harley Limited | Professional & scientific | 2018 |
| B-Jelt Technologies Ltd | Information & communication | 2022 |
| B-Ten Coote Limited | Financial services | 2026 |
| B. Mills Limited | Professional & scientific | 1996 |