| Acting for Change Limited | Other services | 2004 |
| Actinista 2016 Limited | Professional & scientific | 2016 |
| Action FM Limited | Extraterritorial | 2025 |
| Action Pact Ltd | Wholesale & retail | 2018 |
| ACTION4ACCESS Ltd | Health & social care | 2026 |
| Active Forestry Ltd | Agriculture & fishing | 1998 |
| Active Life Yorkshire Limited | Education | 2018 |
| Active Limited | Administrative & support | 2013 |
| AD Astra Accounting Limited | Professional & scientific | 2025 |
| AD HOK Ltd | Extraterritorial | 2012 |
| AD4M Limited | Extraterritorial | 2018 |
| Adaa Management Consultancy Ltd | Wholesale & retail | 2024 |
| Adam Balti & Pizza Limited | Hospitality | 2020 |
| Adam Barbers Harrogate Ltd | Other services | 2021 |
| Adam Fortune Limited | Information & communication | 2022 |
| Adam Fryer Developments Ltd | Construction | 2019 |
| Adam Grange Landscapes Ltd | Administrative & support | 2023 |
| Adam Lloyd Interiors Ltd | Wholesale & retail | 2020 |
| Adam Property Limited | Real estate | 2016 |
| Adapt Media Limited | Professional & scientific | 2008 |
| Adaptaboard Limited | Education | 1997 |
| Adaston Group Limited | Professional & scientific | 2016 |
| Adaston Holdings Ltd. | Administrative & support | 2016 |
| Adaston Investments Limited | Administrative & support | 2016 |
| Adaston Limited | Administrative & support | 2016 |
| Addley Motors Ltd | Manufacturing | 2023 |
| Addy's(Outfitters)Limited | Construction | 1956 |
| Addytec Limited | Professional & scientific | 2016 |
| Adelie Sustainability Ltd | Professional & scientific | 2024 |
| Adevar Limited | Financial services | 2022 |
| Adhd Universe Limited | Other services | 2024 |
| Adhd-One Ltd | Health & social care | 2025 |
| Adigi Holdings Limited | Financial services | 2023 |
| Adigi Ltd | Information & communication | 2010 |
| Adjusting Appointments Limited | Administrative & support | 2005 |
| Adler & Allan Group Limited | Professional & scientific | 2014 |
| ADM Accountants (Yorkshire) Ltd | Professional & scientific | 2012 |
| ADM Property Solutions Ltd | Real estate | 2021 |
| Administrative Support for YOU Ltd | Wholesale & retail | 2024 |
| Admiral Facilities Management Limited | Extraterritorial | 2025 |
| Admiral Solutions Limited | Extraterritorial | 2025 |
| Adrams Limited | Health & social care | 2014 |
| Adrem Development Ltd | Professional & scientific | 2023 |
| Adrem People Development Limited | Professional & scientific | 2010 |
| Adrian Skinner Limited | Health & social care | 2002 |
| Advance Music School Ltd | Education | 2016 |
| Advance Training Systems Ltd | Manufacturing | 2026 |
| Advance Two Civils Limited | Construction | 2024 |
| Advance Two Consulting Limited | Professional & scientific | 2022 |
| Advance Two Limited | Professional & scientific | 2017 |
| Advance Vertex Excellence Ltd | Construction | 2021 |
| Advanced Fire and Rescue Solutions Limited | Extraterritorial | 2026 |
| Advanced Hygienic Contracting Limited | Construction | 1995 |
| Advanced Wellness Chiropractic Clinic Limited | Health & social care | 2010 |
| Advantage Business IT Ltd | Professional & scientific | 2026 |
| Advantage Business Support Ltd | Administrative & support | 2022 |
| Advantage Sport (Harrogate) Limited | Wholesale & retail | 2016 |
| Advo Healthcare Ltd | Wholesale & retail | 2023 |
| Advo Property Ltd | Real estate | 2020 |
| Advotox Limited | Professional & scientific | 2016 |
| AEA Assets Limited | Real estate | 2020 |
| Aehhealthcare Limited | Health & social care | 2023 |
| Aero Engine Global Asset Support Ltd | Transport & logistics | 2020 |
| Aeronautico Ltd | Professional & scientific | 2020 |
| AES Harrogate Ltd | Construction | 2022 |
| Aesculus Avenue Limited | Real estate | 2022 |
| AF Premier Ltd | Financial services | 2013 |
| Afaq Business Solutions Ltd | Wholesale & retail | 2024 |
| AFF Harrogate Ltd | Arts & recreation | 2012 |
| Affinity Individual Mortgage Services Limited | Financial services | 2007 |
| Affordable Classics Limited | Information & communication | 2021 |
| Affordable Rural Homes Limited | Construction | 2019 |
| Affordable Village Homes Limited | Construction | 2019 |
| Afgp Limited | Information & communication | 2001 |
| Afnan Center Ltd | Wholesale & retail | 2022 |
| Afpp Ltd. | Health & social care | 1995 |
| Afterimage Productions Limited | Information & communication | 2011 |
| AG Capital Ventures Limited | Real estate | 2020 |
| Agastya Excotica Holidays Limited | Hospitality | 2024 |
| AGE GAP Limited | Extraterritorial | 2026 |
| Agecare (Eastern) Limited | Extraterritorial | 2016 |
| Agents of Change Ltd | Professional & scientific | 2025 |
| Aggettivo Limited | Administrative & support | 2009 |
| AGH Consulting Limited | Professional & scientific | 2023 |
| Agile Accounts Limited | Professional & scientific | 2019 |
| Agile Code Solutions Limited | Information & communication | 2017 |
| Agora Harrogate Ltd | Hospitality | 2026 |
| Agrifood Investment Advisory LLP | | 2025 |
| Agrilinx Ltd | Professional & scientific | 2023 |
| AGS Associates Executive Search and Consulting Limited | Administrative & support | 2021 |
| Agsnewco Limited | Arts & recreation | 2018 |
| AH Building Limited | Construction | 2025 |
| Ahead of the Game Limited | Information & communication | 2018 |
| Ahlc Solutions Limited | Professional & scientific | 2017 |
| Ahmed Corporation International Ltd | Wholesale & retail | 2024 |
| AHW Legal Ltd | Professional & scientific | 2016 |
| AI Scientific Limited | Extraterritorial | 2025 |
| AI Singularity Ltd | Information & communication | 2022 |
| Aica Data International Ltd | Information & communication | 2023 |
| Aiden Ltd | Extraterritorial | 2013 |