| Arnage Motors UK Limited | Administrative & support | 2019 |
| Arnett Properties Ltd | Real estate | 1946 |
| Arniy Ltd | Wholesale & retail | 2025 |
| Arnold Circus Stool Ltd | Arts & recreation | 2026 |
| Arnold Planning Ltd | Professional & scientific | 2011 |
| Arnold Properties Ltd | Real estate | 2014 |
| Arnold Property Holdings Ltd | Real estate | 2024 |
| Arnold Waste Disposal Limited | Water & waste | 1968 |
| ARO Supercut Ltd | Other services | 2024 |
| Aroma 14 Limited | Hospitality | 2017 |
| Aroma Barbers Limited | Other services | 2018 |
| Aromasene Ltd | Other services | 2025 |
| Aromasoul Limited | Manufacturing | 2024 |
| Arora Investments (Yorkshire) Ltd | Real estate | 2026 |
| Arosti Ltd | Wholesale & retail | 2025 |
| ARP Property Holdings Limited | Financial services | 2023 |
| ARQ Software Ltd | Information & communication | 2026 |
| ARR Portfolio Limited | Real estate | 2023 |
| Arrand Building and Home Maintenance Ltd | Construction | 2020 |
| Arrand Tree Care Ltd | Administrative & support | 2022 |
| Array Model Management Ltd | Other services | 2021 |
| Arrive in Style (Yorkshire) Limited | Transport & logistics | 2005 |
| Arrow Engineering Limited | Manufacturing | 1997 |
| Arrow Publications Limited | Administrative & support | 2008 |
| Arsn Property Ltd | Real estate | 2026 |
| Art Avenue C.I.C. | Construction | 2023 |
| Art Bomb Ltd | Arts & recreation | 2022 |
| Art for Hearts Sake CIC | Health & social care | 2024 |
| Artbrick Limited | Wholesale & retail | 2016 |
| Artcon Management Ltd | Professional & scientific | 2017 |
| Artcore Rocks Ltd | Professional & scientific | 2025 |
| Artdreamin Ltd | Wholesale & retail | 2019 |
| Artek National Engineering Consultancy Ltd | Extraterritorial | 2015 |
| Arteldecor Ltd | Other services | 2018 |
| Artemida Technologies Ltd | Information & communication | 2010 |
| Artemis Builders Limited | Construction | 2026 |
| Artemis Property (Yorkshire) Ltd | Real estate | 2019 |
| Artesian Group Limited | Professional & scientific | 2024 |
| Artesian Spas Limited | Wholesale & retail | 2009 |
| Artesian Spas UK Limited | Wholesale & retail | 2002 |
| Arthemma Ltd | Transport & logistics | 2024 |
| Arthur Rose Properties Limited | Real estate | 2000 |
| Arthur Street (Doncaster) Developments Limited | Real estate | 1992 |
| Artificial Supergrass Sales Limited | Wholesale & retail | 2019 |
| Artisan Annexe Ltd | Construction | 2025 |
| Artisan Loaf Co. Ltd | Extraterritorial | 2026 |
| Artist Comfort Limited | Hospitality | 2017 |
| Artistic Creations Limited | Arts & recreation | 2023 |
| Artistry Clinic SJ Ltd | Other services | 2023 |
| Artopia by Silvia Limited | Wholesale & retail | 2025 |
| Arts and Crafts (Doncaster) Limited | Real estate | 1947 |
| Arts and Culture Community Centre CIC | Education | 2023 |
| Artur Nawrocki Limited | Transport & logistics | 2017 |
| Artur Zelazowski Ltd | Transport & logistics | 2016 |
| Arturroo Ltd | Transport & logistics | 2015 |
| Artvision (U.K.) Limited | Wholesale & retail | 2015 |
| ARU Bagging Limited | Transport & logistics | 2013 |
| Aruk Aero Consultancy Ltd | Professional & scientific | 2025 |
| Arundel Services Design Limited | Professional & scientific | 2015 |
| Arveen Food & Wine Ltd | Wholesale & retail | 2020 |
| Arvid Solutions Ltd | Wholesale & retail | 2026 |
| Aryan Stores Ltd | Wholesale & retail | 2024 |
| Aryy Trans Ltd | Transport & logistics | 2025 |
| AS BIO Cura Ltd | Manufacturing | 2026 |
| AS Construction(Northern) Limited | Construction | 2025 |
| ASA Applications Ltd | Manufacturing | 2026 |
| ASA Solutions Support Ltd | Construction | 2025 |
| Asael Property Traders Ltd | Construction | 2025 |
| Asca Motors Ltd | Transport & logistics | 2024 |
| Ascend Business Coaching Limited | Professional & scientific | 2022 |
| Ascend Learning Solutions Limited | Education | 2013 |
| Ascend Marketing Limited | Professional & scientific | 2023 |
| Ascendant Content Limited | Information & communication | 2022 |
| Ascendant Solutions Ltd | Information & communication | 2016 |
| Ascendia Education Ltd | Extraterritorial | 2026 |
| Ascension Media and Marketing Ltd | Arts & recreation | 2020 |
| ASD Commercial Limited | Real estate | 2019 |
| ASD MOT Ltd | Wholesale & retail | 2016 |
| ASH & Sons Food Limited | Hospitality | 2025 |
| ASH Lewis & Co Limited | Construction | 2024 |
| Ashaab Vision Ltd | Wholesale & retail | 2023 |
| Ashben Design & Conversions Ltd | Wholesale & retail | 2019 |
| Ashbourne Collective Limited | Extraterritorial | 2026 |
| Ashburton Grove Consultants Ltd | Professional & scientific | 2020 |
| Ashcourt Commercials Ltd | Wholesale & retail | 2024 |
| Ashcroft Financial Solutions Limited | Financial services | 2023 |
| Ashfield Court Maintenance Ltd | Households | 2018 |
| Ashfield Gardens Management Company Limited | Households | 2025 |
| Ashfield Grange Services Ltd | Transport & logistics | 2026 |
| Ashley Barrow Ltd | Wholesale & retail | 2022 |
| Ashley Court (Fairford Leys) Ltd | Households | 1999 |
| Ashmad Property Investments Limited | Real estate | 2025 |
| Ashmore Construction Ltd | Construction | 2025 |
| Ashorn Plastering Limited | Wholesale & retail | 2009 |
| Ashton Park Homes Limited | Hospitality | 2005 |
| Ashura Sales Ltd | Wholesale & retail | 2021 |
| Asia Food Shop Limited | Wholesale & retail | 2024 |
| Asian Dragon Store Ltd | Wholesale & retail | 2025 |
| Asiminei Gheorghe Ltd | Hospitality | 2025 |
| ASJ Warwick (Holdings) Ltd | Financial services | 2025 |