| A&B Electrical Solutions Ltd | Construction | 2025 |
| A&B Investment Limited | Real estate | 2025 |
| A&I Properties (Hull) Limited | Real estate | 2020 |
| A&R Roofing Experts Ltd | Construction | 2023 |
| A-Legal Limited | Professional & scientific | 2022 |
| A-Oke Technologies & Consulting Ltd | Information & communication | 2014 |
| A-Plus Delivery Ltd | Transport & logistics | 2022 |
| A-Star Lighting Ltd | Wholesale & retail | 2023 |
| A. C. Plant Limited | Construction | 2005 |
| A. J. S. Invision Limited | Arts & recreation | 2013 |
| A. M. Bell (Properties) Limited | Real estate | 1978 |
| A.A.W. Projects Limited | Administrative & support | 2017 |
| A.F.T Rigging Limited | Construction | 2022 |
| A.L.L.Estates Limited | Real estate | 2018 |
| A.M.D.R. & Co. Limited | Extraterritorial | 2022 |
| A.M.D.R. Limited | Professional & scientific | 1996 |
| A.R. Financial Consulting Limited | Professional & scientific | 2020 |
| A.S Heating Solutions Ltd | Construction | 2022 |
| A.T. Short Installations Limited | Extraterritorial | 2013 |
| A1 Anodising Limited | Manufacturing | 1998 |
| A1 Collectables Limited | Wholesale & retail | 2006 |
| A1 Flooring Ltd | Construction | 2021 |
| A1A Property Ltd | Real estate | 2022 |
| A2 Elite Properties Limited | Real estate | 2025 |
| A217 Car Interior Cleaning Ltd | Wholesale & retail | 2026 |
| A217 Handcarwash Limited | Administrative & support | 2024 |
| A2B Scaffolding Access Ltd | Construction | 2022 |
| A3 Custom Building Services Ltd | Construction | 2026 |
| A3 London Engineering Ltd | Construction | 2020 |
| A4 Design Structural Engineers Ltd | Construction | 2010 |
| AA Frank Hans Limited | Hospitality | 2021 |
| AA Joinery London Ltd | Construction | 2023 |
| AA Surgical Ltd | Health & social care | 2026 |
| AA Telkin Ltd | Real estate | 2016 |
| AA4 Financial Services Limited | Professional & scientific | 2010 |
| AAA Consultancy (PTY) Ltd | Real estate | 2022 |
| AAA Residential Ltd | Real estate | 2022 |
| AAA Star Driving School Ltd | Education | 2021 |
| AAA UK Management Ltd | Professional & scientific | 2024 |
| AAC Traders Ltd | Transport & logistics | 2018 |
| Aacn Holdings Ltd | Financial services | 2022 |
| AAD Investment Properties Ltd | Real estate | 2024 |
| Aahill Trading Ltd | Administrative & support | 2024 |
| AAJ Investments Ltd | Real estate | 2014 |
| AAJ Properties Management Ltd | Real estate | 2014 |
| AAJ Retail Limited | Wholesale & retail | 2022 |
| Aajr Limited | Information & communication | 2018 |
| Aakasha Ltd | Real estate | 2022 |
| AAL Investments Limited | Professional & scientific | 2002 |
| Aalian Services Ltd | Transport & logistics | 2023 |
| Aanya Technologies Limited | Information & communication | 2022 |
| Aaron and Peter Bikes Limited | Wholesale & retail | 2025 |
| Aarya Realty Limited | Real estate | 2020 |
| Aatech Solutions Ltd | Information & communication | 2010 |
| Aavenue Limited | Wholesale & retail | 2023 |
| Aayu Technology Solutions Ltd | Information & communication | 2018 |
| AB Network Solutions Ltd | Transport & logistics | 2019 |
| Abacus Books Ltd | Professional & scientific | 2020 |
| ABB Homes Limited | Real estate | 2025 |
| Abbeyifa Limited | Financial services | 1999 |
| Abbirami Limited | Real estate | 2015 |
| Abbotsford Lessees Limited | Households | 1965 |
| Abbotswood Services Limited | Information & communication | 2008 |
| ABC Medics Ltd | Health & social care | 2022 |
| Abc.London.Construction Ltd | Manufacturing | 2018 |
| Abcfirst Limited | Information & communication | 1999 |
| Abell Heating & Plumbing Ltd | Construction | 2007 |
| ABG 1 Ltd | Financial services | 2023 |
| Abhi & Co UK Limited | Wholesale & retail | 2014 |
| ABI & OLI Enterprises Ltd | Wholesale & retail | 2023 |
| ABI Nails Limited | Other services | 2024 |
| Abkedo Consulting Limited | Professional & scientific | 2013 |
| Able 2 Build & Sons Limited | Construction | 2012 |
| ABM Assets Ltd | Real estate | 2020 |
| ABM Constructions (UK) Ltd | Construction | 2012 |
| ABM Developers Ltd | Construction | 2020 |
| ABM Housing Ltd | Construction | 2021 |
| ABM Residential Ltd | Real estate | 2020 |
| ABM Synergies Ltd | Real estate | 2018 |
| Abodia Ltd | Real estate | 2026 |
| Above ALL Lofts and Extensions Ltd | Construction | 2022 |
| Aboveboard AC Limited | Construction | 2020 |
| Aboveboard On-Demand Ltd | Administrative & support | 2024 |
| ABP Fire&Security Ltd | Administrative & support | 2025 |
| Abro Transport Limited | Transport & logistics | 2022 |
| Absolute Roof Windows Ltd | Construction | 2015 |
| Absolute Roofing + Loft Conversions Limited | Construction | 2017 |
| Absolutt Joinery Limited | Construction | 2011 |
| Abstract Creations London Ltd | Wholesale & retail | 2022 |
| ABZ Construction Ltd | Construction | 2025 |
| AC Electrical& Maintenance Ltd | Construction | 2026 |
| AC Sports Ltd | Manufacturing | 2025 |
| Academedica Limited | Education | 2024 |
| ACC Homes Limited | Real estate | 2024 |
| Accelerator Hire Ltd | Administrative & support | 2021 |
| Accentax Limited | Professional & scientific | 2026 |
| Accessible Emotional Health Ltd | Education | 2023 |
| Accord Resourcing Ltd | Administrative & support | 2021 |
| Accpro Associates Limited | Professional & scientific | 2020 |
| Accurate Accounting Services Limited | Professional & scientific | 2024 |