| Aj’S Express Ltd | Wholesale & retail | 2018 |
| AK Accommodations Ltd | Administrative & support | 2022 |
| AKG Care Enterprise Ltd | Other services | 2013 |
| AKG Property Ltd | Real estate | 2016 |
| Akici Holding Limited | Financial services | 2025 |
| Akincilar Ltd | Hospitality | 2024 |
| AKL Investments Limited | Real estate | 2023 |
| Aklc & Associates Limited | Professional & scientific | 2001 |
| AKR Growth Ventures Ltd | Professional & scientific | 2020 |
| Akrl Homes Ltd | Hospitality | 2025 |
| Aksi Catering Limited | Hospitality | 2025 |
| Aksu Nanny Services Limited | Administrative & support | 2021 |
| Al&Ko Building Limited | Construction | 2020 |
| Al-Mousawi Ltd | Wholesale & retail | 2022 |
| Alahm Investments Ltd | Real estate | 2025 |
| Alan Brydon Consultancy Limited | Other services | 2017 |
| Alasia Consulting Ltd | Information & communication | 2012 |
| Alaz Retailers Limited | Wholesale & retail | 2020 |
| Alberlie Limited | Manufacturing | 2024 |
| Alberly Limited | Real estate | 2020 |
| Albetroz Ltd | Construction | 2009 |
| Albi Car Wash Limited | Other services | 2014 |
| Albinest Ltd | Real estate | 2025 |
| Albury Grove Management Limited | Households | 2002 |
| Alchymia Investments Limited | Real estate | 2020 |
| Alchymy Ltd | Financial services | 2026 |
| Alden Machinery Ltd | Manufacturing | 2024 |
| Aldermere Ltd | Transport & logistics | 2015 |
| Aldershot Turkuaz Limited | Real estate | 2025 |
| Alemao Motorcycles Ltd | Wholesale & retail | 2023 |
| Alesio Ltd | Hospitality | 2022 |
| Alessio Helen Limited | Arts & recreation | 2019 |
| Alevis Limited | Transport & logistics | 2018 |
| Alex Development Ltd | Construction | 2019 |
| Alex Verver Ltd | Health & social care | 2018 |
| Alexander Knight Property Limited | Construction | 2015 |
| Alexandra Logistic Ltd | Wholesale & retail | 2025 |
| Alexandra SE 20 Limited | Real estate | 2013 |
| Alexandrea Occasions Limited | Other services | 2010 |
| Alfred Property Management Limited | Households | 2021 |
| Alignia Ltd | Information & communication | 2025 |
| Aliiefe Ltd | Hospitality | 2023 |
| ALIM139 Ltd | Other services | 2024 |
| Alison K Morgan Ltd | Professional & scientific | 2015 |
| ALL in One Construction Group Ltd | Construction | 2022 |
| ALL Things Good Limited | Wholesale & retail | 2021 |
| Allen Chemical Consultancy Services Limited | Professional & scientific | 2022 |
| Allgas LDN Limited | Construction | 2022 |
| Alliance Security Services Ltd | Administrative & support | 2023 |
| Allnight Tyres Ltd | Wholesale & retail | 2006 |
| Allum Lane (Borehamwood) Management Company Limited | Households | 2012 |
| Alma Healthcare Services Ltd | Public administration | 2018 |
| Almay Properties Limited | Real estate | 2020 |
| Almedco (UK) Limited | Health & social care | 2001 |
| Almighty Security Services Limited | Administrative & support | 2023 |
| Almira Development Ltd | Construction | 2018 |
| Almira IP Limited | Real estate | 2018 |
| Almira IPG Limited | Real estate | 2026 |
| Almira Limited | Real estate | 2016 |
| Almira SPV Ltd | Real estate | 2022 |
| Almira WF42 Limited | Real estate | 2026 |
| Alone Behind Closed Doors Limited | Health & social care | 2025 |
| Alonso Construction Ltd | Construction | 2019 |
| Alorabet Construction Ltd | Construction | 2025 |
| Alow Estates Limited | Real estate | 2008 |
| ALP Construction London UK Ltd | Construction | 2026 |
| ALP Property Limited | Real estate | 2014 |
| Alpa Capital Limited | Financial services | 2022 |
| Alph Fire Limited | Construction | 2021 |
| Alpha Services Contractors Limited | Construction | 2019 |
| Alphabeta Services Limited | Health & social care | 2021 |
| Alpi 68 Ltd | Hospitality | 2024 |
| ALT Equities Limited | Professional & scientific | 2013 |
| Altimour Ltd | Wholesale & retail | 2026 |
| Altinova Properties Limited | Real estate | 2025 |
| Altitude Hampden Road Management Company Limited | Real estate | 2016 |
| Altius&Fortius Limited | Professional & scientific | 2015 |
| Altorfer Financial Management Limited | Financial services | 1990 |
| Altun Finance Limited | Financial services | 2006 |
| Altun Property Consultants UK Limited | Construction | 2016 |
| ALV Fire Protection Limited | Administrative & support | 2015 |
| Alvina Enterprise Ltd | Wholesale & retail | 2026 |
| ALW Couriers Limited | Transport & logistics | 2015 |
| Alzo Edutech Group Limited | Education | 2020 |
| AM Prime Group Ltd | Health & social care | 2019 |
| Amanos Properties Ltd | Real estate | 2023 |
| Amara Driving School Limited | Transport & logistics | 2019 |
| Amas One Ltd | Real estate | 2025 |
| Amasg Ltd | Professional & scientific | 2025 |
| Amazing Blessing Limited | Health & social care | 2013 |
| AMB Logistics Ltd | Transport & logistics | 2017 |
| Ambersun Ltd | Wholesale & retail | 2024 |
| Amcap Consult Limited | Professional & scientific | 2022 |
| Amcap Invest Limited | Real estate | 2020 |
| Ame-It Interpreting Ltd | Professional & scientific | 2009 |
| Amelia Ayerst Design Limited | Professional & scientific | 2019 |
| Amerang Limited | Wholesale & retail | 2013 |
| AMH Electrical Services Ltd | Construction | 2025 |
| Amiad Properties Ltd | Real estate | 2020 |
| AMM Mechanical Ltd | Construction | 2026 |