| ALL Starr Goods Limited | Wholesale & retail | 2025 |
| ALL Steel Fabrications Limited | Manufacturing | 2025 |
| ALL Things Construction Ltd | Construction | 2013 |
| ALL Tonic Ltd | Wholesale & retail | 2020 |
| ALL Towed UP Ltd | Transport & logistics | 2023 |
| ALL Training and Development Ltd | Education | 2016 |
| ALL Walks of Life Network CIC | Education | 2022 |
| ALL Weather Conservatories & Windows Limited | Manufacturing | 2016 |
| ALL Weather Property Services Limited | Administrative & support | 2004 |
| ALL Wright Locksmiths Ltd | Administrative & support | 2026 |
| All-I@Moveo Ltd. | Professional & scientific | 2020 |
| ALL3DEES Care Connect Agency Ltd | Administrative & support | 2024 |
| ALL3DEES Childminding and Travels Adventures Services Limited | Administrative & support | 2024 |
| ALL3DEES Construction Limited | Construction | 2023 |
| Allan Christian Electrical Services Limited | Construction | 2004 |
| Allan Joyce Architects Limited | Professional & scientific | 2006 |
| Allan Karthi Ltd | Wholesale & retail | 2024 |
| Allcampus UK Limited | Transport & logistics | 2018 |
| Allchem (Midlands) Limited | Wholesale & retail | 1996 |
| Allcocks Sheds and Fencing Ltd | Manufacturing | 2022 |
| Allday Mots Limited | Wholesale & retail | 2016 |
| Alldread Estates Limited | Real estate | 2021 |
| Allen & Hale Consultancy Limited | Administrative & support | 2021 |
| Allen (French Polishers) Limited | Transport & logistics | 1948 |
| Allen Associates (Notts) Limited | Administrative & support | 2026 |
| Allen Engineering Limited | Professional & scientific | 1999 |
| Allen Gibson Properties Limited | Real estate | 2020 |
| Allen Landscapes Ltd | Administrative & support | 2025 |
| Allen-Crapper Associates LLP | | 2019 |
| Allens (Plymouth) Limited | Wholesale & retail | 1945 |
| Allens Crankshafts Ltd | Manufacturing | 2008 |
| Allens Performance Limited | Wholesale & retail | 2006 |
| Allenton PJ Ltd | Hospitality | 2023 |
| Allevio (UK) Limited | Professional & scientific | 2020 |
| Allfleet Accident Management Services Limited | Wholesale & retail | 2001 |
| Allgood Outdoors Limited | Administrative & support | 2026 |
| Alliance Leasing Limited | Financial services | 1990 |
| Alliance Painting Ltd | Construction | 2013 |
| Alliance Therapy Ltd | Public administration | 2024 |
| Alliance Traders Limited | Wholesale & retail | 2023 |
| Alliance Training Limited | Education | 2002 |
| Allied Consol Ltd | Real estate | 2018 |
| Allied Merchandise Limited | Professional & scientific | 2013 |
| Allied Safety Limited | Professional & scientific | 2016 |
| Allington Manor Events Limited | Other services | 2013 |
| Allinoneactive Ltd | Other services | 2025 |
| Allinson UX Limited | Information & communication | 2021 |
| Allis-Chalmers Limited | Information & communication | 2007 |
| Alliswell Capital Ltd | Real estate | 2020 |
| Alljay Leisure Limited | Hospitality | 2006 |
| Allmovesuk Limited | Transport & logistics | 2008 |
| Allora Kitchen Ltd | Hospitality | 2026 |
| Allotment 2023 Ltd | Education | 2022 |
| Allotment Education CIC | Education | 2023 |
| Allout Interactive Ltd | Information & communication | 2025 |
| Alloy & Rubber Importers Ltd | Wholesale & retail | 2020 |
| Alloy Engineers Limited | Professional & scientific | 2016 |
| Allscope Ltd | Administrative & support | 2025 |
| Allsop Consult Limited | Professional & scientific | 2013 |
| Allstockgoods Ltd | Wholesale & retail | 2021 |
| ALLTHESMALLTHINGS365 Ltd | Wholesale & retail | 2024 |
| Allton’S Strategy and Consultancy Ltd | Professional & scientific | 2025 |
| Alltruck Distribution Limited | Transport & logistics | 2001 |
| Alltruck Hire Limited | Administrative & support | 2001 |
| Alltruck PLC | Wholesale & retail | 2000 |
| Alltruck Zero Ltd | Extraterritorial | 2020 |
| Allumy Golf Limited | Manufacturing | 2022 |
| Allure Holdings Ltd | Real estate | 2020 |
| Alluvial Ltd | Wholesale & retail | 2021 |
| Allwood Renovations Ltd | Construction | 2025 |
| Ally Architects and Developers Limited | Professional & scientific | 2026 |
| ALM Tax Solutions Ltd | Professional & scientific | 2024 |
| Alma & FLO Properties Limited | Real estate | 2023 |
| Alma DE Cuba Limited | Arts & recreation | 2017 |
| Alma Food Eastwood Ltd | Hospitality | 2024 |
| Alma Road Property Management Company Limited | Households | 2009 |
| Alma Transport HGV Ltd | Transport & logistics | 2026 |
| Almaco Personnel Services Limited | Administrative & support | 2025 |
| Almanar Language School CIC | Education | 2022 |
| Almanzor Ltd | Real estate | 2023 |
| Almeer Radiology Ltd | Health & social care | 2021 |
| Almiro Limited | Real estate | 2013 |
| Almit Healthcare Ltd | Health & social care | 2019 |
| Almns Limited | Information & communication | 2005 |
| Almondbury Dental Limited | Health & social care | 2015 |
| Almondsbury Creative Limited | Hospitality | 2019 |
| Almr Services Ltd | Administrative & support | 2020 |
| Almt Building Ltd | Construction | 2019 |
| Almt Consultants Ltd | Administrative & support | 2013 |
| Almy Ltd | Construction | 2025 |
| Alnafia Ltd | Health & social care | 2015 |
| Alnwickhill Limited | Professional & scientific | 2011 |
| Aloe Naturelle Ltd | Manufacturing | 2024 |
| Alongthedustyroad Ltd | Wholesale & retail | 2020 |
| Alonso Vila Limited | Health & social care | 2015 |
| Aloo Gobi Limited | Hospitality | 2025 |
| Aloowala Ltd | Hospitality | 2018 |
| Alopecoid Opco Ltd | Hospitality | 2021 |
| Alora Restaurant Ltd | Hospitality | 2023 |
| Alpal Ltd | Real estate | 2024 |