| 18 Westcliffe Grove Management Company Limited | Real estate | 1997 |
| 2 Charleville RD Management Company Ltd | Households | 2022 |
| 2 Lancaster Road Ltd | Real estate | 2022 |
| 2SENSE (UK) Ltd | Extraterritorial | 2025 |
| 3 to 4 Station Bridge RTM Company Limited | Households | 2020 |
| 35 Kirkgate Limited | Hospitality | 2025 |
| 3PT Painter and Decorator Ltd | Construction | 2026 |
| 442 Harrogate LLP | | 2019 |
| 442 Motivation Limited | Professional & scientific | 2011 |
| 442 Vehicle Solutions Ltd | Wholesale & retail | 2006 |
| 442 York Ltd | Administrative & support | 2020 |
| 512 (EMA) Limited | Extraterritorial | 2008 |
| 512 (Sheffield) Limited | Extraterritorial | 2008 |
| 512 Limited | Extraterritorial | 2008 |
| 53 Degrees BIM Management Ltd | Professional & scientific | 2023 |
| 5TH Avenue Fashions Limited | Wholesale & retail | 1996 |
| 638 Projects Limited | Information & communication | 2018 |
| 6P'S Consultancy Limited | Professional & scientific | 2006 |
| 6P'S Programming Ltd | Professional & scientific | 2024 |
| A G Turner Electrical Limited | Manufacturing | 2026 |
| A J Horseboxes Ltd | Manufacturing | 2018 |
| A.J. Marshall (Holdings) Ltd | Administrative & support | 2010 |
| A.J. Marshall (Special Steels) Ltd | Wholesale & retail | 1980 |
| A.J.R. Fasteners Limited | Agriculture & fishing | 1984 |
| A.One Feed Supplements Limited | Manufacturing | 1975 |
| AAC and ME Ltd | Information & communication | 2025 |
| Abbeyfield Thirsk & Sowerby Society Limited (the) | Real estate | 1969 |
| Accentide Consulting Ltd | Professional & scientific | 2021 |
| Accipiter Advisory Ltd | Professional & scientific | 2022 |
| AD Perpetuum Limited | Construction | 2018 |
| Adam Robson Electrical Ltd | Construction | 2015 |
| Adaptabox Limited | Manufacturing | 2025 |
| Addisons Electrical and Security Contracting Ltd | Construction | 2020 |
| Addisons Plumbing and Heating Limited | Construction | 2026 |
| Addisons Solar and Renewables Limited | Energy | 2026 |
| Adelaide Mews Management Company (1996) Limited | Households | 1996 |
| Admin Alex Ltd | Professional & scientific | 2025 |
| Adrian Morpeth Footwear Limited | Wholesale & retail | 2001 |
| ADS2 Limited | Administrative & support | 2010 |
| Advanced Professional Services Ltd | Professional & scientific | 2006 |
| Aerium Ltd | Transport & logistics | 2013 |
| Aero-Buffs Ltd | Manufacturing | 2021 |
| Ag-Chem Direct Ltd | Agriculture & fishing | 1999 |
| Agri-Tec Limited | Agriculture & fishing | 1996 |
| Agriculture Limited | Professional & scientific | 2014 |
| Agridigital Ltd | Information & communication | 2025 |
| Agrinomics Limited | Agriculture & fishing | 2017 |
| Agrispray Contractors Limited | Construction | 2013 |
| Agriwash (UK) Limited | Agriculture & fishing | 2006 |
| AHO Mitakuye Oyasin Ltd | Administrative & support | 2025 |
| Aigency Studios Ltd | Professional & scientific | 2025 |
| AJ Ryder Plumbing Services Limited | Construction | 2014 |
| AJ Theatrical Productions Limited | Arts & recreation | 2021 |
| AJB Care and Safeguarding Consultancy Ltd | Health & social care | 2021 |
| AK73 Consulting Ltd | Financial services | 2019 |
| Albion Publishing Limited | Information & communication | 2001 |
| Alchemy IT Solutions Ltd | Information & communication | 2022 |
| ALD Property Investments Ltd | Real estate | 2014 |
| Alex Group of Companies Ltd | Extraterritorial | 2024 |
| Alex Group Property Ltd | Real estate | 2026 |
| Alexis Middleton Solutions Limited | Information & communication | 2013 |
| Alfred Hymas (Ripon) Limited | Professional & scientific | 1960 |
| Alfred Hymas Limited | Agriculture & fishing | 1956 |
| ALL Steels (Scunthorpe) Ltd | Wholesale & retail | 2023 |
| ALL Steels Trading Holdings Limited | Financial services | 2017 |
| ALL Steels Trading Limited | Wholesale & retail | 2001 |
| Allenby Haulage Ltd | Transport & logistics | 2023 |
| Allkan Steels Limited | Wholesale & retail | 2011 |
| Allstars Consulting Ltd | Information & communication | 2023 |
| Almac Property Investments Limited | Real estate | 2018 |
| Alrose Productions Ltd | Administrative & support | 2018 |
| AM Training & Delivery Ltd | Education | 2023 |
| Am:Pm (UK) Limited | Manufacturing | 2013 |
| Amalik Cafe Ltd | Hospitality | 2018 |
| Amber Spring Ltd | Construction | 2024 |
| Ampleforth Village Stores Limited | Wholesale & retail | 2017 |
| Andam Construction Ltd | Construction | 2017 |
| Andrew James Services Ltd | Administrative & support | 2024 |
| Apex Flooring Limited | Construction | 2010 |
| APL Agri Xtra Ltd | Agriculture & fishing | 2020 |
| Applegarth Building Management Limited | Construction | 1997 |
| Applegarth Finance Limited | Professional & scientific | 2019 |
| Aquagronomy Limited | Agriculture & fishing | 2008 |
| Ardoff Limited | Other services | 2016 |
| Argentiere Ventures Ltd | Real estate | 2019 |
| Arthur Haigh Limited | Manufacturing | 2005 |
| Arty Party (Thirsk) Limited | Wholesale & retail | 2018 |
| ASH Park Childcare Services Ltd | Health & social care | 2021 |
| ASH Park Preschool Services Ltd | Health & social care | 2025 |
| Ashbridge Holdings (Yorkshire) Limited | Real estate | 2022 |
| Aspect Building and Civil Engineering Contractors Limited | Construction | 1984 |
| AT Your Leisure Yorkshire Ltd | Real estate | 2024 |
| Aulter Ltd. | Information & communication | 2017 |
| Auto-Tech (Thirsk) Limited | Wholesale & retail | 2002 |
| Autogas 2000 Limited | Wholesale & retail | 1986 |
| AV8-HIRE Ltd | Administrative & support | 2023 |
| Averil Blundell Interior Design LLP | | 2012 |
| AW Accountancy (Thirsk) Limited | Professional & scientific | 2024 |
| Aware HR Ltd | Administrative & support | 2020 |
| Axis Leisure Limited | Financial services | 2013 |