| AWK Services Limited | Professional & scientific | 2009 |
| AWL 11379076 Limited | Information & communication | 2018 |
| Awol a Way of Life Limited | Hospitality | 2018 |
| Awpi Ltd | Real estate | 2023 |
| AWS (MK) Limited | Construction | 2012 |
| AXE & Status Machinery Limited | Wholesale & retail | 2004 |
| AXE Machine Tools Limited | Manufacturing | 1971 |
| AXE Ryan Capital Ltd | Professional & scientific | 2021 |
| Axio Technical Intelligence Holdco Limited | Professional & scientific | 2016 |
| Axio TI Holdings Limited | Professional & scientific | 2015 |
| Axiom Build Ltd | Construction | 2025 |
| Axis Cleaning and Support Services Limited | Administrative & support | 1985 |
| Axis Electronics Limited | Manufacturing | 1994 |
| Axis Group Integrated Services Limited | Administrative & support | 2015 |
| Axis Healthcare Ltd | Administrative & support | 2018 |
| Axis International Ltd | Administrative & support | 2025 |
| Axis Motor Group Ltd | Wholesale & retail | 2025 |
| Axis Security Services Limited | Administrative & support | 1994 |
| AXK Realty Limited | Real estate | 2024 |
| AXK Technology Solutions Ltd | Information & communication | 2022 |
| Axle Autos Mobile Mechanic Ltd | Wholesale & retail | 2018 |
| Axlesoft Ltd | Information & communication | 2010 |
| Axobotics Ltd. | Manufacturing | 2016 |
| Axonflow Ltd | Wholesale & retail | 2026 |
| AYA Living Ltd | Real estate | 2005 |
| Ayaana Estate Agents Ltd | Real estate | 2024 |
| Ayajo Consult Limited | Professional & scientific | 2012 |
| Ayam Mindful Moments Limited | Health & social care | 2026 |
| Ayansh Estates Limited | Real estate | 2021 |
| Ayashi Graphics Ltd | Manufacturing | 2026 |
| Ayaso Nice Food Ltd | Hospitality | 2015 |
| Ayaz and Sons Ltd | Hospitality | 2022 |
| Ayco Scientific Technologies Ltd | Professional & scientific | 2017 |
| Aydin Investment Limited | Construction | 2024 |
| Ayera Ltd | Information & communication | 2014 |
| Ayers Property Services Ltd | Construction | 2024 |
| Ayfields Inventories Ltd | Real estate | 2019 |
| Ayinke Solutions Ltd | Health & social care | 2022 |
| Ayivin Healthcare Limited | Education | 2016 |
| Ayles Group Limited | Construction | 2017 |
| Aylesbury Beauty Clinics Ltd | Other services | 2016 |
| Aylesbury Lounge Limited | Hospitality | 2024 |
| Aylesbury Vale Chiropractic Limited | Health & social care | 2021 |
| Aylix Ltd | Wholesale & retail | 2023 |
| Ayofficeonline Ltd | Wholesale & retail | 2025 |
| Ayolda Limited | Real estate | 2021 |
| AYP Global Limited | Wholesale & retail | 2024 |
| Aypex Roofing Ltd | Construction | 2012 |
| Ayrotv Ltd | Information & communication | 2020 |
| AYS Food Consultancy Ltd | Professional & scientific | 2024 |
| Ayshana Ltd | Hospitality | 2018 |
| Ayurveda International Ltd | Education | 2024 |
| Ayutech Limited | Information & communication | 2014 |
| Ayvi Holdings Ltd | Real estate | 2026 |
| Ayyangya Limited | Information & communication | 2012 |
| AZ Beauty MK Ltd | Other services | 2024 |
| AZ Capital Management Ltd | Administrative & support | 2019 |
| AZ Harmony Ltd | Wholesale & retail | 2020 |
| Azad Plumbing Heating & Electrical Ltd | Other services | 2016 |
| Azalea Beauty Limited | Other services | 2021 |
| Azali Properties Limited | Real estate | 2024 |
| Azam Services Limited | Professional & scientific | 2026 |
| Azar Traders Ltd | Transport & logistics | 2026 |
| Azaya Recruiting Company Limited | Administrative & support | 2024 |
| Azer Consulting Limited | Information & communication | 2012 |
| AZI Estates Ltd | Real estate | 2023 |
| AZI GAS Services Limited | Energy | 2024 |
| AZI Mortgages Ltd | Financial services | 2024 |
| AZI Rentals Ltd | Real estate | 2025 |
| Azide Limited | Professional & scientific | 2010 |
| Azideriva Limited | Information & communication | 2008 |
| Azil Racking and Shelving Limited | Manufacturing | 2016 |
| Azimuth Engineering Consultants Limited | Professional & scientific | 2026 |
| Azimuth International Limited | Information & communication | 2018 |
| Azion Holdings Limited | Health & social care | 2025 |
| Azoodos Blue Limited | Extraterritorial | 2017 |
| AZS Eventing Ltd | Agriculture & fishing | 2022 |
| Aztec Lettings Ltd | Real estate | 2012 |
| Aztec Seven Limited | Wholesale & retail | 2009 |
| Aztech IT Solutions Limited | Information & communication | 2006 |
| AZU Electrical Ltd | Construction | 2016 |
| Azure Bidco Limited | Financial services | 2020 |
| Azure Fintech Consulting Limited | Professional & scientific | 2021 |
| Azure Midco 1 Limited | Financial services | 2020 |
| Azure Midco 2 Limited | Financial services | 2020 |
| Azure Midco 3 Limited | Financial services | 2020 |
| Azure Topco Limited | Financial services | 2020 |
| AZX Limited | Real estate | 2017 |
| Azza Exclusive Ltd | Wholesale & retail | 2025 |
| Azzbex Building & Maintenance Limited | Construction | 2021 |
| Azzieon Ltd | Wholesale & retail | 2014 |
| Azzis Contractors Ltd | Construction | 2023 |
| Azzuri Properties UK Ltd | Real estate | 2021 |
| Azzuro Stands Ltd | Administrative & support | 2026 |
| B & C Recordings Limited | Other services | 1980 |
| B & G Investments Limited | Real estate | 2012 |
| B & H Designs Limited | Information & communication | 2013 |
| B & J Marshall Builders Limited | Construction | 2022 |
| B & J Marshall Limited | Extraterritorial | 2018 |
| B & J Oakgrove Sushi Ltd | Hospitality | 2020 |