| AOH Solutions Ltd | Administrative & support | 2013 |
| Aone Analytics Limited | Information & communication | 2016 |
| AP Appliances Ltd | Wholesale & retail | 2018 |
| AP Fast UK Limited | Real estate | 2021 |
| AP First Couriers Ltd | Transport & logistics | 2019 |
| AP HGV Ltd | Transport & logistics | 2018 |
| AP Structures Limited | Information & communication | 2015 |
| Ap&C Divine Care Ltd | Health & social care | 2023 |
| APA Commercial Vehicle Repair Limited | Wholesale & retail | 2026 |
| APA Transport Limited | Transport & logistics | 2011 |
| Apaya Group Limited | Financial services | 2020 |
| APD Bars Ltd | Hospitality | 2021 |
| Apeg UK Ltd | Wholesale & retail | 2022 |
| Aperitivo Consulting Limited | Professional & scientific | 2024 |
| Aperture Cleaning Services Limited | Administrative & support | 2019 |
| Aperture Commercial Cleaning Services Limited | Administrative & support | 2019 |
| Aperture Contract Services Group Ltd | Administrative & support | 2019 |
| Aperture Window Cleaning (Suburban) Limited | Administrative & support | 2025 |
| Aperture Window Cleaning (Urban) Limited | Administrative & support | 2025 |
| Apertus Automotive Limited | Administrative & support | 2022 |
| Apertus Energy Limited | Professional & scientific | 2022 |
| Apertus Installations Limited | Professional & scientific | 2022 |
| Apex Auto Tyres Limited | Wholesale & retail | 2026 |
| Apex Automotive 1 Ltd | Wholesale & retail | 2025 |
| Apex Automotive 247 Ltd | Wholesale & retail | 2025 |
| Apex Block Cutters Limited | Construction | 1995 |
| Apex Carz Ltd | Transport & logistics | 2024 |
| Apex Chilled Logistics Limited | Transport & logistics | 2015 |
| Apex Consultancy Group Ltd | Real estate | 2021 |
| Apex Decisions Limited | Information & communication | 2022 |
| Apex Ductwork & Ventilation Ltd | Construction | 2026 |
| Apex Innovate Ltd | Manufacturing | 2021 |
| Apex Innovation Group Ltd | Information & communication | 2024 |
| Apex Logistics Solutions Ltd | Transport & logistics | 2019 |
| Apex Powertrain Ltd | Professional & scientific | 2025 |
| Apex Print Solutions Limited | Professional & scientific | 2022 |
| Apex Scaffolding Limited | Other services | 1987 |
| Apexalexai Ltd | Wholesale & retail | 2026 |
| Apexhide Ltd | Wholesale & retail | 2026 |
| APG Works Ltd | Administrative & support | 2017 |
| Aplads Homes Services CIC | Real estate | 2024 |
| Aplads Ltd | Administrative & support | 2022 |
| Apogee Performance Limited | Professional & scientific | 2016 |
| Apollo Branded Content Group International Limited | Professional & scientific | 2015 |
| Apollo Educational Limited | Education | 2019 |
| Apollo Ground Care Limited | Administrative & support | 2024 |
| Apollo Marketing Protection Ltd | Administrative & support | 2020 |
| Apollo Trace Limited | Construction | 2019 |
| App Construct Ltd | Construction | 2025 |
| App Construction Ltd | Construction | 2006 |
| Apple Practice Limited | Health & social care | 2010 |
| Appleby Manor Limited | Wholesale & retail | 1995 |
| Appleby Plumbing & Electrical Services Limited | Construction | 2020 |
| Appleford 2 Renewables Ltd | Professional & scientific | 2023 |
| Appleford 7 Renewables Ltd | Professional & scientific | 2023 |
| Applethwaite Country House Limited | Households | 2003 |
| Applewood Pursuits Ltd | Information & communication | 2019 |
| Applicita Limited | Information & communication | 2012 |
| Apppay Umbrella Limited | Administrative & support | 2017 |
| Approved Business Finance Ltd | Financial services | 2019 |
| Approved Cabs Limited | Transport & logistics | 2024 |
| Approved Commercial Finance Ltd | Financial services | 2019 |
| Approved Driver Training Ltd | Education | 2024 |
| Approved Finance & Leasing LLP | | 2024 |
| Approved Finance Limited | Financial services | 2019 |
| Approved Property Finance Ltd | Financial services | 2019 |
| Approved Tax Ltd | Professional & scientific | 2022 |
| APR Footwear Limited | Other services | 2010 |
| APR Logistics Ltd | Transport & logistics | 2015 |
| Apricus Designs Ltd | Information & communication | 2024 |
| April Logistics Ltd | Transport & logistics | 2023 |
| Aprilis Solutions Limited | Professional & scientific | 2013 |
| Apsil LUA Limited | Real estate | 2017 |
| Apt-Itude Ltd | Professional & scientific | 2009 |
| Aptec IT Solutions Limited | Extraterritorial | 2013 |
| APW Leasehold Management Ltd | Real estate | 2018 |
| AQ Property Invest Ltd | Real estate | 2026 |
| AQD Group Limited | Construction | 2023 |
| Aqeel Raza Ltd | Wholesale & retail | 2025 |
| Aqua Parcs Limited | Arts & recreation | 2017 |
| Aqua Valve Plumbing Ltd | Construction | 2026 |
| Aquaflames Daventry Limited | Manufacturing | 2022 |
| Aquaflow Plumbing & Heating Services Ltd | Construction | 2015 |
| Aquagrace Limited | Administrative & support | 2023 |
| Aqualight (Barry Road) Limited | Real estate | 2019 |
| Aqualight Holdings Limited | Financial services | 2019 |
| Aqualight Swim LLP | | 2025 |
| Aqualight Training Limited | Education | 2019 |
| Aqualight UK Limited | Education | 2004 |
| Aquamark Fish Imports Limited | Wholesale & retail | 2011 |
| Aquarius Gold Limited | Health & social care | 2014 |
| Aquasia Homes Limited | Construction | 2016 |
| Aquavitalogistics Ltd | Transport & logistics | 2024 |
| Aquila Supported Living Services Ltd | Health & social care | 2022 |
| Aquilo Global Logistics Ltd | Transport & logistics | 2025 |
| AR Bricklaying Ltd | Construction | 2025 |
| AR Care Services Ltd | Health & social care | 2015 |
| AR Carpets & Furniture Limited | Wholesale & retail | 2021 |
| AR Construction & Engineering Ltd | Professional & scientific | 2018 |
| AR Media Productions Limited | Information & communication | 2013 |