| Alternate Energy Efficiency Solutions Ltd | Manchester | 2019 |
| Alternate Universe UK Ltd | London | 2022 |
| Alternative Barbering Berkhamsted Limited | St. Albans | 2017 |
| Alternative Barbering Company Hitchin Limited | St. Albans | 2019 |
| Alternative Barbering Harpenden Limited | London | 2017 |
| Alternative Barbering Limited | St. Albans | 2012 |
| Alternative Barbering ST Albans Limited | London | 2017 |
| Alternative Beauty Limited | London | 2014 |
| Alternative Capital RJD Ltd | London | 2025 |
| Alternative Cleaning Solutions & Support Services Ltd | Romford | 2022 |
| Alternative Connections Limited | London | 2026 |
| Alternative Drainage Company Limited | Ossett | 2009 |
| Alternative Eco Solutions UK Ltd | Loughton | 2020 |
| Alternative Groove Limited | Manchester | 2021 |
| Alternative Hair International Ltd | Potters Bar | 2016 |
| Alternative Identity Limited | Doncaster | 2017 |
| Alternative Loans Experience Technologies UK Limited | London | 2022 |
| Alternative Management & Advisory Ltd | London | 2019 |
| Alternative Occasions Ltd | London | 1995 |
| Alternative Pest Solutions Limited | Swadlincote | 2025 |
| Alternative Planning Company Limited | Nottingham | 2013 |
| Alternative Proteins Association | London | 2022 |
| Alternative Recovery Systems Ltd | London | 2026 |
| Alternative Salon Ltd | Hoddesdon | 2011 |
| Alternative Source | Bath | 2010 |
| Alternative USE (Marketing) Limited | Chelmsford | 2002 |
| Alternatively Better Ltd | Bootle | 2026 |
| Alternatives Skin Care Centre Limited | Farnham | 2016 |
| Alternatives Therapy Ltd | Stockport | 2013 |
| Alternotion Consulting Ltd | Fleet | 2007 |
| Alterology Ltd | London | 2024 |
| Altham Road Management Company Limited | Pinner | 2005 |
| Althea Wellness & Aesthetics Ltd | Stafford | 2005 |
| Alti Global Ltd | Fareham | 2019 |
| Alti Limited | Enfield | 2016 |
| Altigo Ltd | Hertford | 2009 |
| Altimedia Ltd | Bromborough | 2018 |
| Altin Falci GF Ltd | Enfield | 2025 |
| Altin Makas Basingstoke Ltd | Basingstoke | 2024 |
| Altin Makas Limited | Halstead | 2022 |
| Altin Makasi Ltd | Peterborough | 2025 |
| Altin Scissors Ltd | Aylesbury | 2020 |
| Altiora Concierge Ltd | Birmingham | 2026 |
| Altiora Outdoors Ltd | Knottingley | 2026 |
| Altitude Drivers Club Ltd | Skipton | 2022 |
| Altitude Management Ltd | Wadebridge | 2013 |
| Altitude Training Solutions Ltd | Halesowen | 2017 |
| Altium (Burnley) Ltd | Crewe | 2026 |
| Altium (Chester) Ltd | Crewe | 2026 |
| Altium Group Ltd | Betley | 2025 |
| ALTIUS8 Limited | London | 2025 |
| Altlanco Ltd | Swindon | 2018 |
| Alto Asset Management Ltd | London | 2022 |
| Alto Hair Limited | South Croydon | 2022 |
| Alto Holdings Limited | Northampton | 2019 |
| Alto Legal Services Limited | Bideford | 2006 |
| Alto Mssp Ltd | Aberdeen | 2009 |
| Alto Technologies Limited | Newbury | 2022 |
| Altoirage Ltd | Birmingham | 2025 |
| Altojosa Limited | Bradford | 2015 |
| Altokay Properties Limited | Romsey | 1970 |
| Altom Tree Care Ltd | Abingdon | 2001 |
| Altomotive Intelligence Limited | Warwick, Warwickshire | 2023 |
| Alton Building Preservation Trust | Swindon | 1992 |
| Alton Christian Care Ltd | Alton | 2012 |
| Alton Masonic Centre Ltd | Alton | 2023 |
| Alton Masonic Centre Management Ltd | Alton | 2023 |
| Alton Nails TD Ltd | Alton | 2025 |
| Alton Tailoring Services Limited | Alton | 2024 |
| Alton's Barbershop Ltd | Manchester | 2022 |
| Altonbarbers Ltd | Aldershot | 2010 |
| Altooma Ltd | London | 2024 |
| Altr Clinic Ltd | Eye | 2025 |
| Altr Hair Ltd | Chester | 2023 |
| Altra Glass Limited | Caernarfon | 2020 |
| Altranis Aesthetics Ltd | Glasgow | 2025 |
| Altreon Limited | Walton | 2025 |
| Altrincham & District Festival CIC | Altrincham | 2017 |
| Altrincham & Hale Muslim Association | Altrincham | 2003 |
| Altrincham (T2) Hairdressing Limited | Alton | 2016 |
| Altrincham BID Limited | Altrincham | 2016 |
| Altrincham Hairdressing Limited | Altrincham | 2015 |
| Altrincham Paradise Nails Ltd | Salford | 2025 |
| Altrincham Town Centre Partnership Limited | Altrincham | 2013 |
| Altrio Barbers Ltd | Blackburn | 2025 |
| Altrlife Yoga Ltd | Burnley | 2023 |
| Altrove Limited | London | 2020 |
| Altru Fundraising Ltd | London | 2019 |
| Altruisk Limited | Wigan | 2007 |
| Altruist Enterprises UK Limited | Birmingham | 2013 |
| Alts & Cleaning Express Ltd | Milton Keynes | 2024 |
| Alts Club Limited | London | 2025 |
| Altsi's Ltd | Solihull | 2017 |
| Altsol Beauty Ltd | Manchester | 2026 |
| Altu London Company Limited | London | 2021 |
| Altun Hair Ltd | Port Talbot | 2023 |
| Altunok Ltd | King'S Lynn | 2024 |
| Altura Consultants Ltd | London | 2025 |
| Altus Financial Ltd | Pembroke Dock | 2015 |
| Altus Intervention Holding Limited | Aberdeen | 2013 |