| ALS Private Limited | London | 2013 |
| ALS Turkish Barbers Ltd | Gateshead | 2023 |
| ALS Upholstery Ltd | Liverpool | 2022 |
| ALS28 Limited | Altrincham | 2023 |
| Alsace FR Ltd | Newtownards | 2025 |
| Alsaffar Mediservices Ltd | Lytham St.Annes | 2023 |
| Alsager Gents Ltd | Stoke-On-Trent | 2024 |
| Alsaha Two Limited | London | 2013 |
| Alsaif Dyers Ltd | Birmingham | 2024 |
| Alsaif for Services Ltd | Manchester | 2024 |
| Alsanol Ltd | Newport | 2023 |
| Alscot Broadband Limited | Stratford-Upon-Avon | 2012 |
| Alscot Limited | Stratford-Upon-Avon | 2011 |
| Alsecure Limited | Manchester | 2006 |
| Alshaer Web Ltd | Manchester | 2021 |
| Alshameri Pick UP Limited | Birmingham | 2019 |
| Alshokor and Partner for Services Ltd | Manchester | 2024 |
| Alsimplyadhd Ltd | Polegate | 2026 |
| Also Leisure Limited | Manchester | 2013 |
| Alsoma Bushbury Limited | Wednesbury | 2015 |
| Alstan Co (UK) Ltd | Cambridge | 2004 |
| Alsten Kōchi Ltd | Diss | 2019 |
| Alston Air Ltd | London | 2016 |
| Alston Moor Partnership Limited | Alston | 2004 |
| Alsuyi Ltd | London | 2007 |
| ALT 21 Nominees (Employees) Limited | London | 2024 |
| ALT 21 Nominees (Investors) Limited | London | 2024 |
| ALT Cottage Ltd | Liverpool | 2022 |
| ALT Hair Ltd | Bicester | 2025 |
| ALT TEC Ltd | Pontypool | 2019 |
| ALT.15 Ltd | Glasgow | 2022 |
| Alt.Fifteen Limited | Newcastle Upon Tyne | 2025 |
| ALT.UN365 Limited | Bournemouth | 2024 |
| Alta Birmingham China Limited | Birmingham | 2005 |
| Alta Hairdressing Limited | Hitchin | 2025 |
| Alta Luci Hair Studio Limited | Ilkley | 2010 |
| Alta Motors Ltd | Aylesbury | 2023 |
| Alta Talent Management Ltd | London | 2025 |
| Alta UK Group Ltd | Watford | 2015 |
| Alta Vista Wellness Ltd | Keighley | 2026 |
| Alta Vita Ltd | London | 2021 |
| Altadicta Limited | London | 1999 |
| Altaer Limited | Hexham | 2016 |
| Altaf Aesthetics Ltd | Nottingham | 2025 |
| Altaf Hemani Ltd | Harrow | 2017 |
| Altaf Investments Limited | Ilford | 2013 |
| Altair Digital Ltd | Saltburn-By-The-Sea | 2024 |
| Altair Helicopters and Professional Services Ltd | Cirencester | 2012 |
| Altair I Ltd | Leigh On Sea | 2021 |
| Altair Signage Ltd | Manchester | 2023 |
| Altaire Enterprises Limited | Aberdeen | 2020 |
| Altamont Limited | London | 1977 |
| Altamuskin Community Association Limited | Omagh | 1996 |
| Altan Limited | Walsall | 2021 |
| Altar of Mercy Evangelical Church Ltd | London | 2024 |
| Altar of Worship Ministry Limited | Telford | 2025 |
| Altara Limited | London | 2024 |
| Altaterra Group Limited | Manchester | 2015 |
| Altav Property Services Limited | Halifax | 2014 |
| Altavista Ltd | Bromsgrove | 2021 |
| Altay Hair & Beauty Limited | London | 1997 |
| Altay Kurdish Barbers Ltd | Gateshead | 2026 |
| Altayb Limited | Manchester | 2016 |
| Altaykay Ltd | Ramsgate | 2025 |
| Altbodyart Ltd | Edinburgh | 2022 |
| Altcom 410 Limited | Stockport | 2006 |
| Altea Property Development Limited | Altrincham | 2007 |
| Alteagroup Limited | London | 2025 |
| Altech Ltd | London | 2018 |
| Alteki Limited | London | 2024 |
| Altemar Enterprise Ltd | London | 2020 |
| Altena Ltd | Wolverhampton | 2018 |
| Altenergy Power Systems UK Ltd | London | 2025 |
| Alter EGO Atelier Ltd | Corby | 2011 |
| Alter EGO Barbers Limited | Stoke-On-Trent | 2026 |
| Alter Girls Ltd | Glasgow | 2026 |
| Alter Therapy Ltd | Twickenham | 2022 |
| Alter-Nation Ltd | Maldon | 2023 |
| Altera Capital Limited | London | 2012 |
| Alteration Station Ltd | Bristol | 2016 |
| Alterations & Ironing Services Ltd | Nuneaton | 2010 |
| Alterations Boutique Chelsea SD Ltd | London | 2024 |
| Alterations Boutique City of London Ltd | Ilford | 2025 |
| Alterations Boutique Hampstead Ltd | London | 2024 |
| Alterations Boutique Islington Ltd | Ilford | 2025 |
| Alterations Boutique Marylebone Ltd | London | 2025 |
| Alterations Boutique MCR Ltd | Manchester | 2025 |
| Alterations Boutique Wimbledon Ltd | Wimbledon Village | 2024 |
| Alterations by Valeria Ltd | London | 2024 |
| Alterations Centre Ltd | Manchester | 2015 |
| Alterations Express Limited | York | 2016 |
| Alterations for Special Occasions Limited | Birmingham | 2016 |
| Alterations Online Limited | Newcastle Upon Tyne | 2014 |
| Alterations Plus Limited | Norwich | 2018 |
| Alterations Studio Limited | Nottingham | 2014 |
| Altered Image Chesham Limited | Chesham | 2001 |
| Altered Image Limited | Chesham | 2001 |
| Altered States Tailoring Specialist Limited | Ilford | 2010 |
| Altered Vibes Limited | London | 1996 |
| Altered Wings Limited | Horsham | 2024 |