| Aledan & Sons Limited | Construction | 2017 |
| Aleef Estates Ltd | Real estate | 2020 |
| Aleem Realty Ltd | Real estate | 2026 |
| Aleema Ltd. | Administrative & support | 2025 |
| Alees Tradings Limited | Wholesale & retail | 2025 |
| Alef Security & Electrical Limited | Construction | 2011 |
| Alegatum Limited | Professional & scientific | 2019 |
| Alegra Payments Limited | Professional & scientific | 2021 |
| Alegria Property Services Ltd | Real estate | 2024 |
| Alehouse Leisure Limited | Hospitality | 2003 |
| ALEJANDRO16 Limited | Administrative & support | 2025 |
| Aleks Property Investments Ltd | Real estate | 2025 |
| Aleksy Property Management Ltd | Households | 2024 |
| Alemdent Limited | Health & social care | 2000 |
| Alen Holdings UK Limited | Real estate | 2026 |
| Alen Norway Consulting and Service Limited | Professional & scientific | 2026 |
| Alen.Learn Ltd | Education | 2017 |
| Alenfirad for Medical Supplies and Cosmetics Trading Ltd | Wholesale & retail | 2026 |
| Alenwi Limited | Health & social care | 2019 |
| Aleo Ltd | Wholesale & retail | 2025 |
| Aleph Business Solutions UK Ltd | Information & communication | 2025 |
| Aleph Construction NW Limited | Construction | 2023 |
| Aleph-Tav Healthcare Services Limited | Health & social care | 2022 |
| Aleppo Premium Limited | Manufacturing | 2020 |
| Aleroz Ltd | Construction | 2024 |
| Alert Fire Solutions Ltd | Construction | 2019 |
| Alert Squad Ltd | Administrative & support | 2023 |
| Alesco Ltd | Transport & logistics | 2026 |
| Alesec Ltd | Households | 2025 |
| Alesen Direct Solutions Ltd | Construction | 2020 |
| Alesha Nonz Community Interest Company | Education | 2026 |
| Alessin International Ltd | Wholesale & retail | 2020 |
| Aletheia Accounting Services Ltd | Professional & scientific | 2023 |
| Aletheia Imaging Solutions Limited | Professional & scientific | 2021 |
| Aletheia Systems Holdings Limited | Information & communication | 2026 |
| Alex & Co Limited | Real estate | 2005 |
| Alex Coleborn Ltd | Information & communication | 2022 |
| Alex Davis (Bedford) Ltd | Health & social care | 2016 |
| Alex Davis (Gosport) Limited | Health & social care | 2011 |
| Alex Davis (Yarmouth) Ltd | Health & social care | 2021 |
| Alex Foundation Household Items | Health & social care | 2021 |
| Alex HAY Consulting Ltd | Information & communication | 2016 |
| Alex Hunt Estates (Lettings) Ltd. | Real estate | 2012 |
| Alex James Atkinson Ltd | Information & communication | 2021 |
| Alex Meakin Ltd | Other services | 2018 |
| Alex Priestley Talent Limited | Information & communication | 2018 |
| Alex Real Estate Property Limited | Real estate | 2026 |
| Alex Supplies Limited | Wholesale & retail | 2017 |
| Alex Taho Ltd | Wholesale & retail | 2023 |
| Alex Tattoos Ltd | Other services | 2021 |
| Alex Trading MCR Ltd | Real estate | 2025 |
| Alex Turner IT Solutions Ltd | Information & communication | 2018 |
| Alex Wiseman Associates Limited | Professional & scientific | 2009 |
| ALEX246CALO Ltd | Transport & logistics | 2017 |
| Alexa Hartle Design Ltd | Information & communication | 2025 |
| Alexandaria Care Limited | Hospitality | 2020 |
| Alexander & Co Accountants Ltd | Professional & scientific | 2022 |
| Alexander & Co Lawyers Ltd | Professional & scientific | 2025 |
| Alexander & Co LLP | | 2008 |
| Alexander & Co Manchester Limited | Extraterritorial | 2010 |
| Alexander Bursk Limited | Professional & scientific | 2012 |
| Alexander Court (Trafford Road) Management Ltd | Real estate | 2017 |
| Alexander CS Ltd | Administrative & support | 2022 |
| Alexander Dawn Ltd | Professional & scientific | 2020 |
| Alexander House Interiors Ltd | Wholesale & retail | 2020 |
| Alexander Joseph Cohen Limited | Financial services | 2022 |
| Alexander Joseph Limited | Extraterritorial | 2011 |
| Alexander Joseph Music Ltd | Wholesale & retail | 2025 |
| Alexander Khanage Ltd | Wholesale & retail | 2024 |
| Alexander Knight Administration Services Ltd | Administrative & support | 2021 |
| Alexander Nicholas Limited | Administrative & support | 2003 |
| Alexander Pointing Ltd | Other services | 2013 |
| Alexander Property Solutions Ltd | Construction | 2022 |
| Alexander Ross (Financial Services) Limited | Professional & scientific | 1981 |
| Alexander Song Limited | Arts & recreation | 2019 |
| Alexander Venture Capital Limited | Real estate | 2025 |
| Alexander Woolfe Ltd | Professional & scientific | 2024 |
| Alexander’S Best One Ltd | Wholesale & retail | 2021 |
| Alexandra Acquisitions Ltd | Real estate | 2019 |
| Alexandra Apartments Management Company Limited | Households | 2003 |
| Alexandra Business Management Ltd | Administrative & support | 2015 |
| Alexandra Ellen Enterprises Ltd | Information & communication | 2025 |
| Alexandra Gate Business Centre Ltd | Real estate | 2009 |
| Alexandra Lodge Care Home Limited | Health & social care | 2022 |
| Alexandra Pension Agency Limited | Administrative & support | 2003 |
| Alexandra Pubs Limited | Hospitality | 2024 |
| Alexandra Residential Care Ltd | Health & social care | 2022 |
| Alexandrahcs Ltd | Administrative & support | 2023 |
| Alexandri Domus Ltd | Real estate | 2022 |
| Alexandria Ashes Limited | Information & communication | 2025 |
| Alexandru Healthcare Limited | Health & social care | 2016 |
| Alexendra Living Care Limited | Administrative & support | 2022 |
| Alexgate Ltd | Real estate | 2018 |
| Alexia Marine Ltd | Professional & scientific | 2019 |
| Alexia Monitoring Ltd | Manufacturing | 2023 |
| Alexis Express Ltd | Transport & logistics | 2023 |
| Alexshara Group Brands Limited | Financial services | 2017 |
| Alexstore Ltd | Wholesale & retail | 2025 |
| Alexsys Bosh Ltd | Professional & scientific | 2010 |
| Alexum Group Limited | Financial services | 2020 |