| Arina Limited | Real estate | 1997 |
| Arinder Bhullar Limited | Wholesale & retail | 2012 |
| Arini Digital Consultancy Limited | Information & communication | 2024 |
| Arios First Ltd. | Administrative & support | 2013 |
| Ariri Restaurant and Bar Limited | Hospitality | 2024 |
| Aris Enterprises Limited | Wholesale & retail | 2025 |
| Arise and Shine Properties Ltd | Real estate | 2022 |
| Arise Supply Ltd | Wholesale & retail | 2024 |
| Arish House Ltd | Households | 2023 |
| Arising Tech Limited | Information & communication | 2022 |
| Arixo Trading Ltd | Wholesale & retail | 2026 |
| Ariya Property Ltd | Real estate | 2020 |
| Ariyan Healthcare Limited | Health & social care | 2017 |
| Ariyan Properties Limited | Real estate | 2021 |
| Arize Trading Ltd | Wholesale & retail | 2025 |
| Ari’S Beauty Bar Limited | Other services | 2025 |
| ARJ Group Limited | Wholesale & retail | 2025 |
| Arja Homes Ltd | Real estate | 2024 |
| Arjan Primeworks Ltd | Construction | 2025 |
| Arjs Contracting Ltd | Financial services | 2015 |
| Arjs Property Management Ltd | Construction | 2014 |
| Arjun Pharma Services Ltd | Wholesale & retail | 2025 |
| Arjune Ltd | Administrative & support | 2024 |
| ARK 13 Ltd | Wholesale & retail | 2016 |
| ARK 8 Consultancy Limited | Professional & scientific | 2012 |
| ARK Airconditioning Limited | Manufacturing | 1990 |
| ARK Aqua Water Solutions Limited | Construction | 2014 |
| ARK Business Finance Ltd | Financial services | 2017 |
| ARK Consulting Services Limited | Administrative & support | 2016 |
| ARK Consulting Solutions Ltd | Health & social care | 2016 |
| ARK Distribution Ltd | Wholesale & retail | 2025 |
| ARK Distributors Limited | Wholesale & retail | 2021 |
| ARK Financial Consultants Limited | Financial services | 2025 |
| ARK Maisson Ltd | Construction | 2026 |
| ARK Microsuction Ltd | Health & social care | 2024 |
| ARK Motors Sileby Limited | Wholesale & retail | 2022 |
| ARK NRI Services Limited | Professional & scientific | 2025 |
| ARK Three Limited | Arts & recreation | 2015 |
| ARK40 Limited | Real estate | 2024 |
| Arkad Limited | Financial services | 1987 |
| Arkall Farm Management Company Limited | Real estate | 2020 |
| Arkbow Ltd | Wholesale & retail | 2024 |
| Arkish Limited | Real estate | 2025 |
| Arks Properties & Management Ltd | Real estate | 2021 |
| Arksys Consultants Ltd | Professional & scientific | 2026 |
| Arkt Travel Ltd | Administrative & support | 2025 |
| Arktech Limited | Information & communication | 2026 |
| ARL Cleans Limited | Administrative & support | 2017 |
| ARL Estates Limited | Real estate | 2021 |
| ARL Property Investments Ltd | Real estate | 2025 |
| ARL Voiceover Ltd | Manufacturing | 2020 |
| Arlen Court Property Management Limited | Real estate | 2009 |
| Arlington Carr Ltd | Other services | 2012 |
| Arlington Fish Limited | Agriculture & fishing | 2022 |
| Arloir Limited | Information & communication | 2024 |
| ARM Culmination Ltd | Health & social care | 2024 |
| ARM Home Developments Ltd | Construction | 2021 |
| ARM Metal Corporation Ltd | Manufacturing | 2024 |
| Arma Holdings Limited | Financial services | 2024 |
| Arma Leicester Ltd | Hospitality | 2013 |
| Armaan Foods (UK) Limited | Extraterritorial | 2013 |
| Armaan Properties Limited | Real estate | 2016 |
| Arman Jewellers UK Limited | Wholesale & retail | 2023 |
| Arman Properties Limited | Real estate | 2017 |
| Arman Singh Builders Limited | Construction | 2023 |
| Armando Investments Limited | Wholesale & retail | 2018 |
| Armison Corporation Ltd | Financial services | 2026 |
| Armison Developments Limited | Construction | 2026 |
| Armitage Farms Ltd | Agriculture & fishing | 2019 |
| Armitage Mitchell & Sons Ltd | Water & waste | 2018 |
| Armitage Property Investments Ltd | Real estate | 2021 |
| Armix Holdings Limited | Other services | 2014 |
| Armoury Demolition and Recycling Limited | Wholesale & retail | 1988 |
| Armr Services Ltd | Information & communication | 2025 |
| Arms Estates Limited | Real estate | 2019 |
| Armsden Racing Limited | Education | 2024 |
| Armson Electrical Services Limited | Construction | 2011 |
| Armstrong Homes (Leicester) Limited | Hospitality | 2015 |
| Armstrong Legal Consultancy Limited | Professional & scientific | 2012 |
| Armtec Courier Services Limited | Transport & logistics | 2015 |
| Arnav Transport Ltd | Transport & logistics | 2025 |
| Arncove Consulting Ltd | Professional & scientific | 2022 |
| Arnd Ltd | Wholesale & retail | 2025 |
| Arngill Logistics Ltd | Transport & logistics | 2014 |
| Arnik Consultancy Ltd | Information & communication | 2013 |
| Arnish Private Ltd | Health & social care | 2019 |
| Arnold & Violet Properties Ltd | Real estate | 2022 |
| Arnold - Transformations Ltd | Professional & scientific | 2015 |
| Arnold KAR Ltd | Information & communication | 2025 |
| Arnott and Ball Ltd | Wholesale & retail | 2024 |
| Arnotts (G.B.) Limited | | 1988 |
| Arnull Waste Management Ltd | Water & waste | 2024 |
| ARO Flooring Ltd | Wholesale & retail | 2026 |
| ARO U.K Ltd | Wholesale & retail | 2023 |
| Arobase Services Ltd | Other services | 2017 |
| Arohi Properties Limited | Real estate | 2018 |
| Aroma Cafe Leicester Ltd | Hospitality | 2025 |
| Aroma Concepts Ltd | Wholesale & retail | 2019 |
| Aroma LAB Ltd | Manufacturing | 2023 |
| Aroma Restaurant Leics Ltd | Hospitality | 2024 |