| Accountancy Solutions (East Anglia) Ltd | Professional & scientific | 2007 |
| Accountancy Solutions (Leicester) Ltd | Professional & scientific | 2020 |
| Accountancy Solutions (Peterborough) Ltd | Professional & scientific | 2011 |
| Accountancy Solutions (South) Ltd | Professional & scientific | 2018 |
| Accountancy Solutions 4U Ltd | Professional & scientific | 2015 |
| Accountant & Solutions Ltd | Professional & scientific | 2018 |
| Accountant KK Solutions Ltd | Professional & scientific | 2026 |
| Accountants With Energy 2 Ltd | Professional & scientific | 2024 |
| Accountants With Energy Ltd | Professional & scientific | 2020 |
| Accounting and Beyond Limited | Professional & scientific | 2013 |
| Accounting Links (UK) Limited | Professional & scientific | 2014 |
| Accountingways Limited | Professional & scientific | 2017 |
| Accounts & Moore Limited | Professional & scientific | 2019 |
| Accounts Assist PB Ltd | Professional & scientific | 2021 |
| Accsend Limited | Extraterritorial | 2015 |
| Accsys Digital Limited | Information & communication | 2001 |
| ACD Building Contractors Limited | Construction | 2018 |
| ACD Enterprise Limited | Administrative & support | 2018 |
| Ace Beauty Bar Ltd | Other services | 2024 |
| Ace Branded Tyres Ltd | Wholesale & retail | 2013 |
| Ace Brickwork and Construction Limited | Construction | 2020 |
| Ace Build (Peterborough) Ltd | Construction | 2026 |
| Ace Capital Limited | Construction | 2020 |
| Ace Coffee and Bagel (Upminster) Limited | Hospitality | 2018 |
| Ace Coffee and Bagel Limited | Financial services | 2018 |
| Ace Contracting Solutions Ltd | Manufacturing | 2024 |
| Ace Creams Limited | Wholesale & retail | 2019 |
| Ace Electra (Peterborough) Limited | Arts & recreation | 2013 |
| Ace Flooring Eastern Limited | Construction | 2014 |
| Ace Interiors (Cambs) Limited | Construction | 2015 |
| Ace Medicals Consultancy Limited | Health & social care | 2009 |
| Ace Mode Ltd | Health & social care | 2022 |
| Ace Property and Holdings Limited | Real estate | 2024 |
| Ace Sales Limited | Professional & scientific | 1981 |
| Ace Technology (UK) Ltd | Professional & scientific | 2007 |
| Ace-Xl Ltd | Information & communication | 2025 |
| ACE4DIGITAL Limited | Construction | 2020 |
| Acebuildequipment Ltd | Wholesale & retail | 2021 |
| Aces Property Maintenance Ltd | Construction | 2023 |
| ACF Workforce Limited | Transport & logistics | 2013 |
| Achilleus Security Management Ltd | Administrative & support | 2019 |
| ACI 27 Trans Ltd | Transport & logistics | 2022 |
| Acitt Ltd | Administrative & support | 2011 |
| ACJ Solutions Limited | Wholesale & retail | 2011 |
| ACL Hospitality Ltd | Hospitality | 2018 |
| ACM ULR Limited | Administrative & support | 1999 |
| Aconley Investments and Enterprises Ltd | Administrative & support | 2012 |
| Acorn Academy Day Nursery Ltd | Health & social care | 2017 |
| Acorn Development Limited | Construction | 1996 |
| Acorn Lodge Luxury Boarding Kennels & Cattery Ltd | Other services | 2013 |
| Acoustic Associates Limited | Professional & scientific | 2005 |
| ACP Locum Ltd | Health & social care | 2023 |
| ACR 100 Ltd | Wholesale & retail | 2020 |
| ACR24 Transport Ltd | Transport & logistics | 2024 |
| Acrefield Solutions Limited | Agriculture & fishing | 2018 |
| Acresoft Computing Limited | | 1986 |
| Acreven Ltd | Professional & scientific | 2021 |
| Acro Aeronautical Services Limited | Professional & scientific | 1983 |
| ACS1 Ltd | Transport & logistics | 2019 |
| ACT Trans Ltd | Transport & logistics | 2014 |
| Action House Services Limited | Real estate | 2017 |
| Action in Futures Ltd | Education | 2025 |
| Action Project (UK) Ltd | Professional & scientific | 2008 |
| Action Recruitment Services Ltd | Administrative & support | 2023 |
| Activ Property Management Limited | Administrative & support | 2009 |
| Activ Red Ltd | Hospitality | 2013 |
| Activ Staffing and Support Limited | Administrative & support | 2012 |
| ACTIV8AI Ltd | Information & communication | 2025 |
| Active Alliance Limited | Wholesale & retail | 2004 |
| Active Chiropractic Limited | Health & social care | 2004 |
| Active Cooling & Airflow Services Limited | Manufacturing | 2012 |
| Active Engineering Services Ltd | Construction | 2019 |
| Active Learning Group Limited | Financial services | 2025 |
| Active Linx Ltd | Manufacturing | 1999 |
| ACTIVE8 IT Limited | Other services | 2005 |
| Actondev Limited | Construction | 2023 |
| Actt Developments Limited | Construction | 2018 |
| Actuarial Project Services Limited | Professional & scientific | 2010 |
| ACU Print Limited | Manufacturing | 2000 |
| Acumo-Accountancy Ltd | Professional & scientific | 2021 |
| Acupuncture Association of Chartered Physiotherapists Limited | Administrative & support | 2006 |
| AD Carpets Flooring and Blinds Ltd | Construction | 2021 |
| AD Data Analytics Ltd | Information & communication | 2019 |
| AD Eyecare Ltd | Health & social care | 2025 |
| AD LIB Band Ltd | Professional & scientific | 2009 |
| AD Management Opco-A Ltd | Other services | 2025 |
| AD Oundle Store Ltd | Wholesale & retail | 2025 |
| AD Publishing Limited | Information & communication | 2024 |
| AD Realty Ltd | Real estate | 2024 |
| Ad&Rr Construction Ltd | Construction | 2018 |
| Adam Aziz Properties Limited | Real estate | 2005 |
| Adam Czaplinski Security Limited | Administrative & support | 2023 |
| Adam Dumrul Ltd | Extraterritorial | 2025 |
| Adam Fitch Limited | Agriculture & fishing | 2006 |
| Adam Prime Car Sales Ltd | Wholesale & retail | 2024 |
| Adam S Logistocs Ltd | Transport & logistics | 2018 |
| Adam Shop Ltd | Hospitality | 2024 |
| Adam Sroka Ltd | Administrative & support | 2017 |
| Adam Transport Services Limited | Transport & logistics | 2025 |
| Adam W Ltd | Transport & logistics | 2018 |