| A2Z Gondals Ltd | Administrative & support | 2025 |
| A308 Central Park Ltd | Real estate | 2026 |
| A325 Ltd | Information & communication | 2024 |
| A3H Developments Ltd | Construction | 2023 |
| A4S Cloud Solutions Limited | Information & communication | 2012 |
| A6 Autos Ltd | Wholesale & retail | 2022 |
| AA Build Management Ltd | Real estate | 2022 |
| AA Food & Beverage UK Ltd | Wholesale & retail | 2026 |
| AA Healthcare Solutions Ltd | Professional & scientific | 2024 |
| AA Homes Consultancy Ltd | Administrative & support | 2024 |
| AA Medihealth Ltd | Health & social care | 2025 |
| AAA Medicolegal Reporting Ltd | Professional & scientific | 2010 |
| AAF Financial Services Ltd | Professional & scientific | 2025 |
| AAG Properties MAN Ltd | Real estate | 2025 |
| AAI Freight Services Ltd | Transport & logistics | 2019 |
| AAI Global Holdings Limited | Financial services | 2021 |
| AAL Group Ltd | Wholesale & retail | 2021 |
| Aamaira Traders Ltd | Wholesale & retail | 2024 |
| Aamchi Mumbai (2022) Ltd | Hospitality | 2022 |
| AB Hub Services Ltd | Financial services | 2023 |
| AB Nova Ltd | Construction | 2015 |
| Abchem Solutions Ltd | Public administration | 2018 |
| Abdullah Awan Limited | Health & social care | 2022 |
| Abeemus Limited | Real estate | 2022 |
| Abibih Ltd | Wholesale & retail | 2024 |
| Abney and Cove Limited | Professional & scientific | 2021 |
| Aboms Ltd | Wholesale & retail | 2017 |
| Above and Below Structures Ltd | Professional & scientific | 2023 |
| ABP Medical Billing Limited | Professional & scientific | 2012 |
| ABS Fast Food Stockport Limited | Hospitality | 2025 |
| Absolute DJS Limited | Professional & scientific | 2006 |
| Absolute Home Improvements (NW) Ltd | Construction | 2019 |
| Absolute Solar Panels Limited | Construction | 2014 |
| Absolutely Gleaming Ltd | Administrative & support | 2005 |
| Academy Court Limited | Real estate | 2005 |
| Acasta Europe Limited | Financial services | 2010 |
| ACB Property Investments Limited | Real estate | 2009 |
| Accelerated Delivery Ltd | Professional & scientific | 2011 |
| Accounts Draft Limited | Information & communication | 2025 |
| Ace Chattel Ltd. | Professional & scientific | 2008 |
| Ace Constructions Solutions Ltd | Construction | 2023 |
| ACF P Limited | Construction | 2023 |
| ACH Joinery Limited | Construction | 2024 |
| Achari Limited | Hospitality | 2025 |
| Acharya Property Services Limited | Real estate | 2021 |
| Ackersley Court Limited | Households | 1967 |
| Acresfield Estates Limited | Real estate | 1938 |
| Acrobat Consulting and Marketing Limited | Professional & scientific | 1995 |
| Acru Electric Tool Manufacturing Co. Limited(The) | Manufacturing | 1954 |
| Acru Manufacturing Limited | Financial services | 2025 |
| Acsol Limited | Other services | 2007 |
| Acsons Investments Limited | Financial services | 2025 |
| Activated Care Ltd | Health & social care | 2023 |
| Active Acquisition Limited | Real estate | 2022 |
| Active Communities Events Ltd | Arts & recreation | 2019 |
| Acun Handyman Services Ltd | Construction | 2020 |
| AD Advisory Services Limited | Professional & scientific | 2019 |
| AD IT Networks Limited | Information & communication | 2015 |
| Adalan Cyber First Ltd | Information & communication | 2023 |
| Adatex Ltd | Wholesale & retail | 2021 |
| Addama Limited | Real estate | 2022 |
| Added Extra Limited | Professional & scientific | 2015 |
| Additive Consulting Limited | Professional & scientific | 2019 |
| Adegko Foods Limited | Hospitality | 2024 |
| Adelphi Property Group Holdings Limited | Real estate | 2012 |
| Adey Electronics Limited | Wholesale & retail | 2011 |
| Adgan Electrics Ltd | Manufacturing | 2024 |
| Adgiftsonline Limited | Administrative & support | 1998 |
| Adil MED Ltd | Health & social care | 2015 |
| ADK Property (MCR) Limited | Real estate | 2024 |
| ADM Civils and Rail Ltd | Construction | 2020 |
| Admk Investments Ltd | Real estate | 2024 |
| Adnia Anaesthesia Ltd | Health & social care | 2025 |
| Adoptomise AI Limited | Information & communication | 2026 |
| Adoreign Limited | Wholesale & retail | 2025 |
| Adparatio PM Ltd | Construction | 2020 |
| Adrhealth Ltd | Professional & scientific | 2021 |
| Adrian Cameron Limited | Administrative & support | 2006 |
| Adsation Ltd | Professional & scientific | 2024 |
| Adsparq. Ltd | Professional & scientific | 2025 |
| Adult Toy Box Ltd | Wholesale & retail | 2024 |
| Advance HN Developments Limited | Professional & scientific | 2018 |
| Advanced Concrete Floors Ltd | Construction | 2026 |
| Advanced Hall Sensors Limited | Manufacturing | 2011 |
| Advancedtelematics Ltd | Administrative & support | 2022 |
| Advice Centre Group Ltd | Financial services | 2022 |
| Advice Supermarket Ltd | Professional & scientific | 2010 |
| Advoco (UK) Holdings Limited | Professional & scientific | 2011 |
| Advoco Consulting Services Ltd | Professional & scientific | 2009 |
| ADW Interiors & Developments Ltd | Construction | 2026 |
| Adzuki Systems Ltd | Information & communication | 2013 |
| AE International Trading Limited | Wholesale & retail | 2019 |
| AEC Medicals Limited | Health & social care | 2013 |
| Aesica Queenborough Limited | Manufacturing | 2007 |
| Aesthetic Pro Ltd | Construction | 2024 |
| Aesthetically Beautiful Limited | Other services | 2026 |
| Aesthetics by Karen Whitehead Ltd | Health & social care | 2019 |
| Aesthetics Medispa Ltd | Administrative & support | 2025 |
| Aevian Holdings Limited | Financial services | 2026 |
| AF Property Group Limited | Real estate | 2021 |