| A.V Service Ltd | Wholesale & retail | 2023 |
| A.V.A Drywall Limited | Construction | 2025 |
| A.V.A Interiors Ltd | Construction | 2019 |
| A.V.E Weld Construct Ltd | Manufacturing | 2025 |
| A.V.Structures Ltd | Construction | 2020 |
| A.Varghese & SON Limited | Financial services | 2019 |
| A.Vincent Solicitors Ltd | Professional & scientific | 2016 |
| A.W. Cavanagh (Spitalfields) Limited | Wholesale & retail | 1986 |
| A.W. Group Services Ltd | Construction | 2025 |
| A.W. Lumb (Midlands) Limited | Extraterritorial | 1976 |
| A.W. Lumb (Northern) Limited | Extraterritorial | 1980 |
| A.W. Pristine Cleaning Ltd | Administrative & support | 2025 |
| A.W.(Pvt) Consulting Ltd | Professional & scientific | 2017 |
| A.W.A.D Security Ltd | Administrative & support | 2025 |
| A.W.E Construction Ltd | Construction | 2026 |
| A.W.F Fletcher and Daughters LLP | | 2020 |
| A.W.Lumb & Co.Limited | Wholesale & retail | 1964 |
| A.W.M Traders Ltd | Wholesale & retail | 2026 |
| A.W.O.L Music Limited | Arts & recreation | 2009 |
| A.Wilson Consultants Ltd | Administrative & support | 2021 |
| A.Wilson Recruitment Ltd | Administrative & support | 2024 |
| A.Xodus C.I.C. | Information & communication | 2022 |
| A.Xodus Media Group Ltd | Information & communication | 2021 |
| A.Y Architecture Ltd | Professional & scientific | 2025 |
| A.Y.R Property Services Ltd | Construction | 2024 |
| A.You.K Limited | Information & communication | 2024 |
| A.Z Electric Ltd | Construction | 2019 |
| A.Z Investements Limited | Hospitality | 2021 |
| A.Z Investments 2 Ltd | Hospitality | 2023 |
| A.Z Specialist Ltd | Public administration | 2019 |
| A.Z. Motors Limited | Financial services | 1938 |
| A.Z.A.R Limited | Real estate | 2013 |
| A/B Street Ltd | Information & communication | 2025 |
| A/F Nordica Ltd | Financial services | 2026 |
| A/H Houseremoval Services Ltd | Manufacturing | 2025 |
| A/O Credit Control Ltd | Extraterritorial | 2010 |
| A/O UK 1 Limited | Financial services | 2019 |
| A/O VC UK Limited | Financial services | 2021 |
| A/Political LND Ltd | Information & communication | 2025 |
| A/Political Ltd | Information & communication | 2008 |
| A/V Revolution Ltd | Information & communication | 2011 |
| A/X Services Ltd | Construction | 2016 |
| A0 Design Studio Ltd | Professional & scientific | 2018 |
| A01 Holdco Limited | Financial services | 2021 |
| A01 Ventures Limited | Real estate | 2024 |
| A0203 Capella Limited | Real estate | 2023 |
| A04 Ltd | Real estate | 2025 |
| A1 24 X 7 Limited | Transport & logistics | 2016 |
| A1 Accounting Services Ltd | Professional & scientific | 2020 |
| A1 Accounting UK Limited | Professional & scientific | 2009 |
| A1 Accounts Ltd | Information & communication | 2008 |
| A1 Advisors Limited | Professional & scientific | 2023 |
| A1 Advisory Services LLP | | 2025 |
| A1 Affinity Limited | Professional & scientific | 2013 |
| A1 AI Ltd | Information & communication | 2025 |
| A1 Alignment Limited | Wholesale & retail | 2017 |
| A1 Apparels Ltd | Wholesale & retail | 2018 |
| A1 Associates Ltd | Wholesale & retail | 2018 |
| A1 Autotech Ltd | Wholesale & retail | 2024 |
| A1 Autoz Limited | Wholesale & retail | 2011 |
| A1 Bespoke Joinery Ltd | Construction | 2012 |
| A1 Brooke Road Limited | Households | 2018 |
| A1 Build for YOU Ltd | Real estate | 2021 |
| A1 Building Services Solutions Ltd | Construction | 2016 |
| A1 Business Support Ltd | Administrative & support | 2025 |
| A1 Cabs & Truck UK Ltd | Transport & logistics | 2021 |
| A1 Candy Crush Ltd | Wholesale & retail | 2024 |
| A1 Capital Lettings Limited | Real estate | 2016 |
| A1 Carlton Doyle Limited | Construction | 2002 |
| A1 Carpets and Flooring Limited | Wholesale & retail | 2016 |
| A1 Catering Limited | Hospitality | 2024 |
| A1 Chicken Bites Ltd | Hospitality | 2025 |
| A1 Civil Engineering Limited | Construction | 2008 |
| A1 Cladding Limited | Wholesale & retail | 2022 |
| A1 Clearance and Maintenance Ltd | Water & waste | 2026 |
| A1 Commerce Ltd | Wholesale & retail | 2023 |
| A1 Commodities Limited | Wholesale & retail | 2019 |
| A1 Components Limited | Wholesale & retail | 2007 |
| A1 Concierge Ltd | Hospitality | 2018 |
| A1 Concise Consulting Limited | Professional & scientific | 2025 |
| A1 Connect Ltd | Wholesale & retail | 2025 |
| A1 Construction Services 87 Ltd | Construction | 2025 |
| A1 Consulting Ltd | Professional & scientific | 2022 |
| A1 Contractors Services Ltd Ltd | Construction | 2026 |
| A1 Conversion Ltd | Construction | 2023 |
| A1 Cooked Meats Ltd | Manufacturing | 2003 |
| A1 Crystal Cleaning Ltd | Administrative & support | 2025 |
| A1 Cyber Ltd | Information & communication | 2024 |
| A1 Dairies Limited | Real estate | 2011 |
| A1 Data Analytics Ltd | Information & communication | 2020 |
| A1 Deliveries Ltd | Administrative & support | 2017 |
| A1 Denim Ltd | Manufacturing | 2021 |
| A1 Dental Laboratory Ltd | Health & social care | 2015 |
| A1 Designs Limited | Professional & scientific | 1990 |
| A1 Dgtl Ltd | Information & communication | 2026 |
| A1 Driver Training Ltd | Education | 2026 |
| A1 DRY Clean Service Limited | Other services | 2018 |
| A1 DRY Cleaners Limited | Other services | 2017 |
| A1 East London Care 24/7 Ltd | Health & social care | 2025 |
| A1 Electrical 24/7 Ltd | Construction | 2026 |