| A Pawsey Limited | Professional & scientific | 2006 |
| A R Car Rentals Limited | Administrative & support | 2025 |
| A Star Bathrooms Limited | Construction | 2019 |
| A Toner Upvc Specialist Ltd | Construction | 2017 |
| A Touch of Simplicity Ltd | Wholesale & retail | 2022 |
| A Williams Services Limited | Professional & scientific | 2019 |
| A&A Best Construction Ltd | Construction | 2014 |
| A&A Consulting (Essex) Limited | Professional & scientific | 2024 |
| A&A Window Cleaning Ltd | Administrative & support | 2024 |
| A&C Express Ltd | Transport & logistics | 2025 |
| A&D 24 Ltd | Transport & logistics | 2023 |
| A&D Fire Sprinklers Ltd | Construction | 2022 |
| A&H Van Services Ltd | Water & waste | 2025 |
| A&Joseph Transport Ltd | Transport & logistics | 2025 |
| A&K Commercial Property Ltd | Real estate | 2023 |
| A&L Construct Ltd | Construction | 2019 |
| A&M Building Solutions Ltd | Construction | 2026 |
| A&M Fire Limited | Construction | 2023 |
| A&N Provisions Ltd | Health & social care | 2024 |
| A&Nr Construction Ltd | Construction | 2020 |
| A&R Williams Holdings Ltd | Real estate | 2024 |
| A&R Williams Installation & Maintenance Ltd | Construction | 2023 |
| A&S Hoisa Ltd | Wholesale & retail | 2025 |
| A&S Roofing and Upvc Ltd | Construction | 2026 |
| A&Zaks Transport Ltd | Transport & logistics | 2019 |
| A. Hurry Plumbing Limited | Construction | 2018 |
| A. J. S. Brickwork Consultancy Limited | Construction | 2003 |
| A.C.Butt(Builders)Limited | Construction | 1953 |
| A.C.E.L.M Ltd | Professional & scientific | 2023 |
| A.C.H. Contracts Limited | Construction | 2018 |
| A.C.T Plumbing Solutions Ltd | Construction | 2020 |
| A.D. Build Floors Ltd | Construction | 2023 |
| A.K.B Superior Interior Installation's Limited | Construction | 2018 |
| A.L.S. Investment Properties Ltd | Real estate | 2026 |
| A.M. Sewell & Co. Limited | Professional & scientific | 2000 |
| A.P. Hollings & Sons Limited | Real estate | 2003 |
| A.R.Dellow Limited | Professional & scientific | 2012 |
| A.S.P.I.R.E Sports Management Services Limited | Arts & recreation | 2024 |
| A.T.A.R Signalling Ltd | Construction | 2014 |
| A.T.E. Management Limited | Administrative & support | 2018 |
| A.T.E. Trustee Limited | Professional & scientific | 2024 |
| A1 Autos Limited | Wholesale & retail | 2015 |
| A1 Choice Property Limited | Real estate | 2018 |
| A1 Waste Clearance Limited | Other services | 2014 |
| A11 Creative Limited | Arts & recreation | 2025 |
| A2 Team Ltd | Construction | 2016 |
| A2A Foods Limited | Manufacturing | 2016 |
| A2B Administration Ltd | Administrative & support | 2025 |
| A2T Fashion Ltd | Hospitality | 2007 |
| A2Z Emphaty Care UK Ltd | Health & social care | 2024 |
| A3E Auto Ltd | Wholesale & retail | 2023 |
| AA Amalgamations Limited | Wholesale & retail | 2025 |
| AA Class Painters Ltd | Construction | 2020 |
| AA Virgo Investment Limited | Education | 2020 |
| Aaasafehome Limited | Real estate | 2018 |
| AAB Financial Services Ltd | Financial services | 2015 |
| AAI Cargo Limited | Transport & logistics | 2020 |
| AAI Ecotrans Limited | Transport & logistics | 2025 |
| AAI European Logistics Ltd | Transport & logistics | 2016 |
| AAI FAR East Limited | Transport & logistics | 1998 |
| AAI Freight Fusion Ltd | Transport & logistics | 2026 |
| AAI Freight Solutions Ltd | Transport & logistics | 2026 |
| AAI Holdings Limited | Real estate | 2005 |
| AAI International Limited | Administrative & support | 2017 |
| AAI Limited | Transport & logistics | 1994 |
| AAI Logistics Limited | Administrative & support | 2006 |
| AAI Projects Limited | Transport & logistics | 2019 |
| AAI Verus Limited | Transport & logistics | 2018 |
| AAI Worldwide Limited | Transport & logistics | 2002 |
| Aaimc Ltd | Health & social care | 2024 |
| Aalog Ltd | Transport & logistics | 2026 |
| Aamruk Limited | Real estate | 2024 |
| Aanacki Transport Limited | Transport & logistics | 2015 |
| AAO Services Limited | Professional & scientific | 2022 |
| Aapu Ltd | Real estate | 2023 |
| Aaron Anton Limited | Real estate | 2022 |
| Aaron Services Group Limited | Other services | 2025 |
| Aaron Tait Ltd | Professional & scientific | 2026 |
| Aaroo Ltd | Real estate | 2021 |
| Aarvo UK Limited | Information & communication | 2026 |
| Aaryav Global Stores Limited | Wholesale & retail | 2023 |
| Aashu Catering Ltd | Hospitality | 2026 |
| Aawaaw Ltd | Real estate | 2015 |
| AB Castings and Management Limited | Administrative & support | 2013 |
| AB Commercial Property Holdings Ltd | Administrative & support | 2018 |
| AB Electrical Services (Essex) Ltd | Construction | 2022 |
| AB Estate Solutions Ltd | Transport & logistics | 2023 |
| AB London Services Limited | Other services | 2017 |
| AB Nest Ltd | Wholesale & retail | 2025 |
| AB Salute Gym Bishop Ltd | Arts & recreation | 2022 |
| AB Salute Gym Brentwood Ltd | Arts & recreation | 2011 |
| AB Salute Gym Countrywide Ltd | Real estate | 2022 |
| AB Salute Gym Lakeside Ltd | Arts & recreation | 2013 |
| AB Salute Gym Ltd | Real estate | 2010 |
| AB Salute Gym Romford Ltd | Arts & recreation | 2022 |
| AB Salute GYM80 Ltd | Arts & recreation | 2024 |
| AB Secure Ltd | Administrative & support | 2026 |
| Abaris Plastics Limited | Wholesale & retail | 2017 |
| Abbate Building and Groundwork Services Limited | Construction | 2022 |
| Abbey House (Leicester) Limited | Real estate | 2016 |