| Alty Law Ltd | Preston | 2023 |
| Altyn Tepe Ltd | Bristol | 2019 |
| Altype Plans Limited | Elgin | 2002 |
| Altyx Group Ltd | London | 2020 |
| ALU Architectural Art Europe Holdings Ltd | Daventry | 2017 |
| ALU Deox UK Limited | Stockton On Tees | 2025 |
| ALU Living Style Limited | London | 2026 |
| ALU Worx Ltd | London | 2025 |
| Alu-Glaze & Door Engineers Ltd | Walsall | 2023 |
| Aluciant Ltd | London | 2020 |
| Aluco Advisers Limited | Attleborough | 2013 |
| Aluco Ecology Limited | Helston | 2005 |
| Alucoat Consultants Limited | Old Hatfield | 2025 |
| Aludra Bess Ltd | Kings Langley | 2020 |
| Aludum Ltd | Stratford-Upon-Avon | 2021 |
| Alugatesireland Limited | Maghera | 2023 |
| Alula Coaching Ltd | London | 2022 |
| Alula Consulting Ltd | London | 2024 |
| Alula Engineering Limited | Glasgow | 2011 |
| Alum Consulting Limited | Emsworth | 2013 |
| Alum ZEB Khan Ltd | Birmingham | 2026 |
| Aluma Humanitarian Solutions Ltd | Croydon | 2025 |
| Alume Ltd | Cheltenham | 2020 |
| Alumination Ventures Ltd | London | 2021 |
| Aluminium & Glazing Services Limited | South Yorkshire | 2007 |
| Aluminium & Plastics Systems (Holdings) Ltd | Lisburn | 2015 |
| Aluminium Bronze Valves Limited | Keighley | 2005 |
| Aluminium Coating Services Ltd | Shifnal | 2022 |
| Aluminium Developments Group Limited | Wednesbury | 2016 |
| Aluminium Profiles UK Ltd | Keighley | 2013 |
| Aluminium Pulleys Limited | Essex | 1969 |
| Aluminium Suppliers Limited | Hebden Bridge | 2024 |
| Alumm UK Limited | London | 2019 |
| Alumni Compliance Solutions Ltd | London | 2024 |
| Alumnilab Ltd | London | 2018 |
| Alun Barnes Consulting Ltd | Leeds | 2024 |
| Alun Bedding Coaching and Consulting Limited | Bury St. Edmunds | 2024 |
| Alun Davies Marketing Ltd | Leeds | 2019 |
| Alun Evans | Haverfordwest | 2008 |
| Alun James & Co Limited | Southend On Sea | 2004 |
| Alun Jones Family Law Limited | Cardiff | 2010 |
| Alun Jones Limited | London | 2023 |
| Alun Marks Limited | Tunbridge Wells | 2020 |
| Alun Powell Ltd | Worthing | 2023 |
| Alun Rees Learning Limited | Ripon | 2014 |
| Alun Smith Surveying Services Ltd | Ruthin | 2017 |
| Alun Vaughan Consultancy Limited | Manchester | 2023 |
| Alun Walsh Limited | Mildenhall | 2011 |
| Alun Williams Consultancy Limited | Clyro | 2021 |
| Alunet Systems Limited | Alfreton | 2016 |
| Alupac Ltd | Staines-Upon-Thames | 2024 |
| Alupanel Ltd | Birmingham | 2020 |
| Alur Payments Consultants Ltd | Benfleet | 2020 |
| Alura Candles Limited | Tring | 2001 |
| Alura Group UK Ltd | Leighton Buzzard | 2020 |
| Alura Imaging Ltd | Edinburgh | 2025 |
| Alura Ltd | West Wickham | 2025 |
| Alure Business Services Ltd | Bedford | 2025 |
| Alurisal Ltd | Wigan | 2026 |
| Alusayd Pharma Limited | Leeds | 2014 |
| Alusen Limited | Liskeard | 2015 |
| Alushi Systems Limited | Solihull | 2025 |
| Alusight Facade Design Ltd | Aberdare | 2024 |
| Alusis Ltd | Montrose | 2019 |
| Aluta Quality Consultancy Ltd | Berkhamsted | 2024 |
| Aluvise Consulting Limited | Guildford | 2024 |
| Aluztra BIO Limited | Salisbury | 2014 |
| Alva Advisory Ltd | North Shields | 2021 |
| Alva Advisory Partners Ltd | Reading | 2026 |
| Alva Consult UK Ltd | Berkhamsted | 2019 |
| Alva Consultancy Ltd | Bovey Tracey | 2015 |
| Alva Consultancy Services Limited | Milton Keynes | 2015 |
| Alva Consulting Limited | Edinburgh | 2009 |
| Alva D Limited | London | 2025 |
| Alva Horizon Limited | London | 2026 |
| Alva International Limited | London | 2025 |
| Alva Tech Ltd | London | 2019 |
| Alvago Limited | London | 2010 |
| Alvah Developments Limited | Petersfield | 2007 |
| Alvah Management and Property Services Limited | Aberdeen | 2020 |
| Alvalan Ltd | Hemel Hempstead | 2025 |
| Alvand Communications Ltd | Harlow | 2018 |
| Alvanko Ltd | London | 2018 |
| Alvanter Global Ltd | London | 2025 |
| Alvara Property Ltd | Liverpool | 2025 |
| Alvarado & Co Limited | London | 2016 |
| Alvarado Global Consulting Limited | London | 2021 |
| Alvarado Street Limited | Bath | 2026 |
| Alvaran Group Ltd | Birmingham | 2025 |
| Alvarez & Marsal Cayman Holdings Limited | London | 2025 |
| Alvarez & Marsal Denmark General Partner Limited | London | 2005 |
| Alvarez & Marsal Europe Limited | London | 2005 |
| Alvarez & Marsal Gfd-Europe Holdings Limited | London | 2007 |
| Alvarez & Marsal Nominees Limited | London | 2006 |
| Alvarez & Marsal Taxand-Uk Holdings Limited | London | 2007 |
| Alvarium Design Ltd | London | 2018 |
| Alvarium Penge Limited | London | 2021 |
| Alvarium Streatham Limited | London | 2020 |
| Alvarium Talent Limited | London | 2021 |
| Alvaro Back VET Limited | Pulborough | 2019 |