| 000 Medical Limited | Health & social care | 2026 |
| 06678526 Limited | Manufacturing | 2008 |
| 14RYK Limited | Wholesale & retail | 2019 |
| 161 Takeaway Services Ltd | Hospitality | 2025 |
| 16301605 Ltd | Manufacturing | 2026 |
| 1ST for Blinds, Shutters & Curtains Direct Ltd | Manufacturing | 2025 |
| 1ST Steps Housing &Support CIC | Health & social care | 2026 |
| 3 Aces Medical Imaging & Reporting Consultancy Ltd. | Health & social care | 2020 |
| 3 West Park Limited | Households | 1989 |
| 3 Wise Monkeys Creative Limited | Extraterritorial | 2012 |
| 321 Properties Limited | Real estate | 2019 |
| 3GATES Property Maintenance Limited | Administrative & support | 2008 |
| 3MB Limited | Financial services | 2020 |
| 4 Spital Bridge Management Limited | Households | 2025 |
| 57 Practice Limited | Health & social care | 2026 |
| 59A Huddersfield Road (Mirfield) Limited | Real estate | 2025 |
| 59PROCOM Limited | Administrative & support | 2013 |
| 669 Distribution Limited | Transport & logistics | 2016 |
| A & M Markham Limited | Real estate | 2016 |
| A & M Seafoods Limited | Wholesale & retail | 2022 |
| A & R Noble Construction Limited | Construction | 2004 |
| A & S Domestics Limited | Wholesale & retail | 2019 |
| A B Mcguire Limited | Construction | 2003 |
| A Day to Remember Horse Drawn Ltd | Other services | 2020 |
| A Effendi Limited | Extraterritorial | 2025 |
| A J G Installations Limited | Construction | 2012 |
| A J Lowton Limited | Professional & scientific | 2007 |
| A J Properties (Yorkshire) Limited | Real estate | 2023 |
| A K Agricultural and Forestry Contractors Ltd | Agriculture & fishing | 2023 |
| A P Swift Limited | Extraterritorial | 1998 |
| A Small World Day Nursery Ltd | Health & social care | 2018 |
| A to Z Scrap Cars and Vans Ltd | Wholesale & retail | 2023 |
| A.D. Summerscales Painting & Decorating Contractors Limited | Construction | 2010 |
| A.P.C. Electrical Limited | Manufacturing | 2002 |
| A.T.A. (Builders & Plumbers Merchants) Limited | Wholesale & retail | 1996 |
| A.T.S. Utilities & Civils Ltd | Construction | 2026 |
| A.V.Roe & Company Limited | Professional & scientific | 2009 |
| A10 Properties Limited | Real estate | 1998 |
| A3E Consulting Ltd | Professional & scientific | 2025 |
| AA Rider Ltd | Hospitality | 2025 |
| Aabp Limited | Wholesale & retail | 2017 |
| Aasz Yorkshire Limited | Construction | 2022 |
| AB Aquatic Supplies Ltd | Wholesale & retail | 2019 |
| AB Gardening Supplies Ltd | Wholesale & retail | 2018 |
| Able Groundcare Limited | Administrative & support | 2026 |
| Abra Estates Ltd | Real estate | 2026 |
| Ace Autostore UK Limited | Wholesale & retail | 2021 |
| Ackl Limited | Construction | 2021 |
| Acme Accountants Limited | Professional & scientific | 2022 |
| Acorn Analytical Services Ltd | Administrative & support | 2003 |
| Acre Valley Ltd | Wholesale & retail | 2013 |
| Acres Car Sales Limited | Wholesale & retail | 2016 |
| Acume UK Limited | Financial services | 2009 |
| AD Catering Services Ltd | Hospitality | 2021 |
| Addictive Audio Ltd | Administrative & support | 2023 |
| Adept Resourcing Engineering Ltd | Administrative & support | 2016 |
| Adjuva Care Services Ltd | Public administration | 2025 |
| ADM Marketing Limited | Professional & scientific | 2002 |
| Admiral Building (UK) Ltd | Manufacturing | 2015 |
| Adpm Professional Services Ltd | Professional & scientific | 2018 |
| ADT Construction Limited | Construction | 2019 |
| Advance Technical Systems Ltd | Manufacturing | 2005 |
| Advansec Ltd | Information & communication | 2024 |
| Aeon Online Solutions Limited | Professional & scientific | 2018 |
| Aeterna Properties Limited | Real estate | 2026 |
| Aetos Property Ltd | Real estate | 2023 |
| Afta Party Records Limited | Information & communication | 2022 |
| After Dark (Dress Hire) Limited | Wholesale & retail | 2001 |
| Afterhours Club Limited | Wholesale & retail | 2026 |
| AG Joinery & Garden Rooms Limited | Construction | 2026 |
| Agency Dealmasters Ltd | Information & communication | 2019 |
| Agency Elite Recruitment Limited | Administrative & support | 2026 |
| AH Contracting Limited | Water & waste | 2010 |
| Ahbw Ltd | Wholesale & retail | 2023 |
| AHJ Hearing Care Limited | Health & social care | 2026 |
| Ahmed’S Cleckheaton Ltd | Hospitality | 2024 |
| Airedale SO Productions Ltd | Arts & recreation | 2025 |
| AJL Care Holdings Limited | Real estate | 2024 |
| AJM Electrical Solutions Ltd | Construction | 2021 |
| AJS Recruitment Services Limited | Administrative & support | 2019 |
| AKA Mars Rail Limited | Professional & scientific | 2020 |
| Akan Consulting Limited | Information & communication | 2014 |
| Akasfabrics Ltd | Wholesale & retail | 2022 |
| Akram Investments Holding Ltd | Real estate | 2020 |
| AKT Capital Investments Limited | Real estate | 2019 |
| AL Herts Homes Ltd | Real estate | 2020 |
| Al-Makkah Ltd | Wholesale & retail | 2019 |
| Aletheia Lettings Consultancy Limited | Real estate | 2024 |
| Alexander Surgical Limited | Health & social care | 2019 |
| Alfred Bagnall & Sons (East Midlands) Limited | Construction | 1972 |
| Alfred Bagnall & Sons (Leeds) Limited | Construction | 1989 |
| Alfred Bagnall & Sons (London) Limited | Construction | 1972 |
| Alfred Bagnall & Sons (Midlands) Limited | Construction | 1972 |
| Alfred Bagnall & Sons (North East) Limited | Construction | 1974 |
| Alfred Bagnall & Sons (North) Limited | Construction | 1972 |
| Alfred Bagnall & Sons (North-West) Limited | Construction | 1972 |
| Alfred Bagnall & Sons (Property Development) Limited | Construction | 2017 |
| Alfred Bagnall & Sons (Restoration) Limited | Construction | 1969 |
| Alfred Bagnall & Sons (Scotland) Limited | Professional & scientific | 2007 |
| Alfred Bagnall & Sons (South Wales) Limited | Construction | 1976 |