| Aisthetik Ltd | Health & social care | 2025 |
| Aitchsquared Ltd | Health & social care | 2011 |
| AJ Bakeries Sidmouth Ltd | Hospitality | 2020 |
| AJ Bakeries Topsham Ltd | Hospitality | 2020 |
| AJ Delivery Services Ltd | Transport & logistics | 2026 |
| AJ Kelly Orthopaedics Limited | Health & social care | 2018 |
| AJ Trees Ltd | Agriculture & fishing | 2016 |
| Aj's (Weymouth) Limited | Hospitality | 2018 |
| Aj's Home Cooking Ltd | Hospitality | 2025 |
| AJE Asset Management Ltd | Professional & scientific | 2023 |
| AJG Consultancy (Exeter) Limited | Information & communication | 2018 |
| AJG Flooring Ltd | Construction | 2022 |
| AJH Carpentry Limited | Construction | 2024 |
| AJM Aesthetics Academy Ltd | Other services | 2023 |
| AJR Fitness Limited | Arts & recreation | 2024 |
| AJR Mobile Mechanics Ltd | Wholesale & retail | 2020 |
| AJR Recruitment Limited | Administrative & support | 2019 |
| AJS Developments (Greenfield House) Ltd | Real estate | 2021 |
| AJS Property Maintenance Ltd | Construction | 2003 |
| AJW Partners Limited | Information & communication | 2023 |
| AK Prop Holding Ltd | Real estate | 2022 |
| Aka&Co Ltd | Wholesale & retail | 2024 |
| Akabe Limited | Hospitality | 2024 |
| Akkeron Construction Services Ltd | Construction | 2023 |
| Akkeron Leisure Limited | Administrative & support | 2011 |
| AKU Properties Limited | Real estate | 2017 |
| Akumal Property Limited | Hospitality | 2020 |
| Akurik Ltd | Health & social care | 2020 |
| AL & AF Foods Limited | Manufacturing | 2022 |
| AL Caseta Limited | Financial services | 2023 |
| AL Molo Dorchester Ltd | Hospitality | 2026 |
| Alan Baldwin Services Limited | Professional & scientific | 2019 |
| Alan Dedicoat Enterprises Limited | Information & communication | 2008 |
| Alansway Limited | Wholesale & retail | 2010 |
| Alarm the Public Risk Management Association | Other services | 2004 |
| Alarmtec Limited | Construction | 1977 |
| Alastal Transport Services Ltd | Transport & logistics | 2020 |
| Alathari GP Limited | Health & social care | 2023 |
| Albercutx Towers Limited | Financial services | 2024 |
| Albion Accommodation Limited | Real estate | 2017 |
| Albion Engineering Ltd | Professional & scientific | 2023 |
| Albion Property and Garden Maintenance Ltd | Construction | 2025 |
| Alborough Ltd | Other services | 2023 |
| ALC Investments Ltd | Hospitality | 2017 |
| ALD (Redhills) Ltd | Extraterritorial | 2023 |
| Aldens Properties Ltd. | Real estate | 1982 |
| Alder and Alder Limited | Arts & recreation | 2005 |
| Alderfield Limited | Professional & scientific | 2014 |
| Alderville Consulting Limited | Arts & recreation | 2020 |
| Alderville Investments Limited | Real estate | 2015 |
| Aleryani Ltd | Wholesale & retail | 2023 |
| Alesia Logistics Group Ltd | Transport & logistics | 2026 |
| Aleviem Limited | Real estate | 2023 |
| Alex Griffin Limited | Health & social care | 2013 |
| Alex Rosen Associates Limited | Professional & scientific | 2003 |
| Alex Wysocki Photography Limited | Professional & scientific | 2022 |
| Alexander James COX Limited | Construction | 2002 |
| Alexander Maitland Ltd | Professional & scientific | 1996 |
| Alexander-Brown Properties Ltd | Real estate | 2017 |
| Alexandra Aesthetics Ltd | Other services | 2025 |
| Alexis Investigations Limited | Administrative & support | 2024 |
| Alextra Ltd | Information & communication | 1998 |
| Alfa Grey Properties Ltd | Real estate | 2020 |
| Alfarid (UK) Ltd | Hospitality | 2013 |
| Alfarid Property Ltd | Real estate | 2020 |
| Alfie Photo Booths Limited | Arts & recreation | 2013 |
| ALI Diamond Ltd | Wholesale & retail | 2024 |
| Align Finance Ltd | Professional & scientific | 2011 |
| Alim Systems Limited | Information & communication | 2010 |
| Alin Mircea Logistics Limited | Transport & logistics | 2017 |
| Alinea Interactive Limited | Information & communication | 2005 |
| Alira Heating Limited | Construction | 2022 |
| Alison Channing Hair Ltd | Other services | 2024 |
| Alistair Claxton Consulting Ltd | Professional & scientific | 2024 |
| ALL About Bars Ltd | Hospitality | 2022 |
| ALL Capital Holdings Ltd | Financial services | 2024 |
| ALL Capital Ltd | Administrative & support | 2023 |
| ALL Capital Management Ltd | Administrative & support | 2023 |
| ALL Capital Receivables Finance Ltd | Financial services | 2025 |
| ALL Flooring Direct Limited | Construction | 2026 |
| ALL GAS Services SW Ltd | Construction | 2019 |
| ALL Machinery Sales Limited | Wholesale & retail | 2020 |
| ALL New Newcourt Management Ltd | Households | 2013 |
| ALL Points Ltd | Construction | 2026 |
| ALL Saints 2009 (Management Company) Limited | Households | 2009 |
| ALL Saints Design Ltd | Professional & scientific | 2011 |
| ALL Steel for Building Limited | Manufacturing | 2019 |
| All-Steps Formation Ltd | Extraterritorial | 2023 |
| All-Steps Formation Riding Limited | Arts & recreation | 2019 |
| Allegro Enterprises Limited | Professional & scientific | 2010 |
| Allen Trump Holdings Limited | Financial services | 2009 |
| Allgo Services Ltd | Administrative & support | 2024 |
| Alli Fast Food Ltd | Hospitality | 2024 |
| Alloy & Scratch Master Ltd | Wholesale & retail | 2023 |
| Allstock Limited | Wholesale & retail | 2004 |
| Allure Fashions Limited | Extraterritorial | 2003 |
| Ally (Exeter) Limited | Financial services | 2012 |
| ALM Fire and Security Limited | Construction | 2025 |
| ALM Group Holdings Limited | Financial services | 2025 |
| Alma Road (Brixham) Flats Management Limited | Households | 1981 |