| Alumet Tooling Limited | Sidcup | 2024 |
| Alumia Partnership (UK) Limited | Leigh-On-Sea | 2025 |
| Alumia Smrf Ltd | Leigh-On-Sea | 2021 |
| Aluminati Ltd | Royston | 2021 |
| Alumini Holdings Limited | Newbury | 1994 |
| Aluminium Dunkerque Acquireco 2 Limited | London | 2021 |
| Aluminium Dunkerque Acquireco Limited | London | 2021 |
| Aluminium France Industries UK Ltd | London | 2018 |
| Aluminox Holdings Ltd | Norwich | 2025 |
| Alumitech Holdings Ltd | Holsworthy | 2022 |
| Alumni Ltd | Bolton | 2025 |
| Alun Smith Ltd | Pulborough | 2025 |
| Alun Thomas Limited | London | 2012 |
| Aluna Holding Ltd | Domonic Drive | 2024 |
| Aluna Leaf Holding Ltd | Ruislip, | 2025 |
| Aluna Life Ltd | Swansea | 2014 |
| Aluna Partners Ltd | London | 2021 |
| Alusru Holdings Ltd | Belfast | 2021 |
| Alutrade Management Limited | Oldbury | 2024 |
| Alutrade Management Team Investments Limited | Oldbury | 2016 |
| Aluuva Limited | Essex | 2013 |
| ALV Groupco Limited | London | 2022 |
| Alva Estates Limited | Dunfermline | 1961 |
| Alva Street Holdings Limited | Edinburgh | 2016 |
| Alva Wealth Limited | Edinburgh | 2024 |
| Alvacorpinc Ltd | London | 2025 |
| Alvah Limited | Ashford | 2023 |
| Alvance Aluminium Service UK Ltd | Leamington Spa | 2020 |
| Alvara Group Ltd | London | 2025 |
| Alvarez & Marsal Advances Limited | London | 2011 |
| Alvarez Holdings Limited | Hitchin | 2020 |
| Alvarium Fund Managers (UK) Limited | Birmingham | 2015 |
| Alvarium Home Reit Advisors Limited | Brighton | 2020 |
| Alvaro Barrington Production Limited | London | 2022 |
| Alvea | Norwich | 2020 |
| Alveberdon Farming Limited | Shaftesbury | 1997 |
| Alvechurch Investments Limited | Narberth | 2003 |
| Alvedius Ltd | Northampton | 2015 |
| Alveier Limited | Southampton | 2013 |
| Alver Investments Limited | Bury St. Edmunds | 2024 |
| Alver Mortgage Solutions Ltd | Gosport | 2020 |
| Alveria Claim Group Ltd | Bolton | 2016 |
| Alveron Limited | London | 2026 |
| Alverstone Mortgages Limited | Gateshead | 2021 |
| Alves Ventures Limited | London | 2020 |
| Alvesholds Investments Limited | London | 1964 |
| Alvestoke Finance Limited | Stafford | 2013 |
| Alveston Holdings Limited | Bilston | 2019 |
| Alveum Limited | London | 2026 |
| Alvfrase Global Limited | Worthing | 2025 |
| Alvi Health and Safety Consultancy Company Ltd | Horton Road, | 2016 |
| Alvida Limited | Bolton | 2024 |
| Alviez Capital Ltd | Ruislip | 2023 |
| Alvina Global Ltd | Warwick | 2025 |
| Alvine Capital Management Limited | London | 2005 |
| Alvis Limited | Camberley | 1962 |
| Alvs Holdings Ltd | Leicester | 2024 |
| ALW Financial Solutions Ltd | Leeds | 2026 |
| ALW Investments Ltd | Dungannon | 2022 |
| ALW Oakwells Holdings Limited | Coventry | 2025 |
| ALW Property Limited | Newtownabbey | 2016 |
| Alwa Holdings Ltd | London | 2026 |
| Alwabry Global Limited | London | 2017 |
| Alwakeel International Ltd | London | 2017 |
| Alwan Holdings Ltd | Blackburn | 2026 |
| Always Ready Security Ltd | London | 2021 |
| Always VFM Ltd | London | 2020 |
| Always Wright Mortgages Limited | Waterlooville | 2019 |
| Alwayse Ball Units Ltd. | Aston | 2022 |
| Alwayse Futures Limited | Birmingham | 2022 |
| Alwayson Funding Limited | Pinner | 2026 |
| Alwen Hough Johnson Limited | | 1974 |
| Alwyn Phillips Trading Limited | Northwood Hills | 2013 |
| Alwyne Capital Ltd | London | 2016 |
| ALX Capital Limited | London | 2023 |
| ALX Exceptional Vehicles Limited | York | 2023 |
| Alxine Consulting Ltd | Glasgow | 2011 |
| ALY Capital Ltd | Bolton | 2025 |
| Alyassiricar Limited | Harrow | 2025 |
| Alycidon Limited | Ilkeston | 2014 |
| Alycidon Technologies Limited | Ilkeston | 2014 |
| Alyoi Limited | London | 2016 |
| Alysia Caring (London) Limited | London | 2024 |
| Alyssa Trading Holdings Limited | London | 2017 |
| Alyssia Investments Ltd | London | 2022 |
| Alytus Midco Limited | Nottingham | 2024 |
| Alzahraa Exchange & Remittance Ltd | London | 2015 |
| Alzain Ltd | London | 2010 |
| Alzamel Group Holdings Limited | Stanmore | 2025 |
| Alzamel Group UK Ltd | Stanmore | 2020 |
| Alzir Ltd | Ilford | 2025 |
| Alzoh.Events Ltd | London | 2025 |
| Alzol Limited | Lancaster | 2025 |
| AM & CG Limited | Preston | 2024 |
| AM & Co Holdings Limited | Glasgow | 2016 |
| AM & NM Co Limited | Walsall | 2026 |
| AM & RS Capital Ltd | Stockport | 2021 |
| AM & SM Holdings Ltd | Fleetwood | 2018 |
| AM & Sons Holdings Limited | Stockton-On-Tees | 2025 |
| AM & TL Wade Holdings Ltd | Mansfield | 2018 |