| ABC Digital Solutions (SW) Ltd | Administrative & support | 2021 |
| ABC Digital Solutions Limited | Other services | 2001 |
| Abiss Consultancy Ltd | Administrative & support | 2017 |
| Ablewell Limited | Health & social care | 2011 |
| ABM Transport Ltd | Transport & logistics | 2018 |
| Abnercare Ltd | Health & social care | 2017 |
| Abnercare Properties Ltd | Households | 2022 |
| Abnercare Recruitment Agency Ltd | Health & social care | 2024 |
| Aboutwellness Limited | Health & social care | 2011 |
| Absolute Beauty Ltd | Other services | 2016 |
| Absolutely Capital Ltd | Wholesale & retail | 2025 |
| Abstract Commercial Services Ltd | Administrative & support | 2017 |
| Abtz Ltd | Transport & logistics | 2025 |
| AC Fire Project Management Limited | Professional & scientific | 2014 |
| Acacia Tree Ltd | Hospitality | 2020 |
| Academy of Emotional Therapeutic Counselling Ltd | Education | 2021 |
| Acaelia Home Design Ltd | Construction | 2018 |
| Accensia Limited | Professional & scientific | 2024 |
| Access Assured Limited | Extraterritorial | 2018 |
| Access-Ability (UK) Ltd | Administrative & support | 1999 |
| Account Invest Ltd | Wholesale & retail | 1990 |
| ACCOUNTANTS2BUSINESS Ltd | Professional & scientific | 2005 |
| Ace Construction Solutions Ltd | Construction | 2019 |
| Ace Creative Media Ltd | Professional & scientific | 2024 |
| Ace English Limited | Education | 2024 |
| Ace Garden Rooms Ltd | Construction | 2021 |
| Acha Holiday Rentals Limited | Hospitality | 2026 |
| Achaari Cheshire Ltd | Hospitality | 2023 |
| Achaarionline Limited | Hospitality | 2022 |
| Achieve Social Care Ltd | Administrative & support | 2025 |
| Ackery Brands Limited | Manufacturing | 2012 |
| Acquired Access Ltd | Construction | 2020 |
| Acre Marketing Ltd | Administrative & support | 2015 |
| Acresbrook Investments Limited | Administrative & support | 2020 |
| Action Display Ltd | Administrative & support | 2021 |
| Active Maps Limited | Professional & scientific | 1997 |
| Activideo Communications Limited | Information & communication | 2002 |
| Actpro Limited | Professional & scientific | 2023 |
| ACU Medical Services Ltd | Extraterritorial | 2024 |
| Acumen E-Business Limited | Real estate | 2007 |
| Acumen IT Limited | Information & communication | 2009 |
| Acupuncture Regulatory Authority Ltd | Public administration | 2022 |
| Adam Barber Macclesfield Ltd | Other services | 2022 |
| Adam Russell Events Limited | Administrative & support | 2018 |
| Adaptive Business Development Ltd | Professional & scientific | 2026 |
| Adaptive Orgs Ltd | Professional & scientific | 2025 |
| ADB BSL Interpreting Limited | Professional & scientific | 2025 |
| Addison Walker Ltd | Construction | 2013 |
| Addoceo Consultancy Limited | Professional & scientific | 2014 |
| Adelphi Holdings (UK) Limited | Professional & scientific | 2012 |
| Adelphi Insurance Brokers Ltd. | Financial services | 2012 |
| Adelphi Special Risks Limited | Financial services | 2013 |
| Adlington Autobody Ltd | Wholesale & retail | 2023 |
| Adlington Court Ltd | Real estate | 2023 |
| Adlington Finance Limited | Financial services | 2010 |
| Adlington Golf Centre Limited | Other services | 1998 |
| Adlington Memorial Park Limited | Other services | 2012 |
| Admin by Carrie Ltd | Administrative & support | 2025 |
| Adobie Property Ltd | Real estate | 2018 |
| Adomedia Ltd | Information & communication | 2006 |
| Adorable Dori Community Interest Company | Manufacturing | 2024 |
| Adrian Whittaker Limited | Transport & logistics | 2012 |
| Adroit Designs & Print Limited | Professional & scientific | 2004 |
| Adroit Economics Holdings Limited | Financial services | 2024 |
| Adullam Limited | Real estate | 2020 |
| Advanced Company Software Ltd | Information & communication | 2009 |
| Advanced MSK Solutions Ltd | Health & social care | 2025 |
| Advanced Vacuum Solutions Limited | Manufacturing | 2022 |
| Advent Construction Limited | Construction | 1999 |
| Advicetrade Limited | Administrative & support | 2020 |
| Adworx Media Ltd | Professional & scientific | 2023 |
| AEF Commercial Consulting Limited | Professional & scientific | 2017 |
| Aelius AI Limited | Information & communication | 2024 |
| Aeolus Technology Ltd | Professional & scientific | 2010 |
| AER Wholesale Ltd | Wholesale & retail | 2020 |
| Aero Resolve Ltd | Professional & scientific | 2024 |
| Aero Sport International Limited | Extraterritorial | 2008 |
| Aerofoil Energy (Holdings) Limited | Financial services | 2020 |
| Aerofoil Energy Limited | Manufacturing | 2013 |
| Aerospace Trading Ltd. | Transport & logistics | 2011 |
| Aesscentials Global Limited | Manufacturing | 2025 |
| Aestha Ltd | Health & social care | 2011 |
| Aesthetic by DJP Ltd | Other services | 2025 |
| Affinity Technical Services Ltd | Information & communication | 2011 |
| Affirmfirst Limited | Information & communication | 2015 |
| Affirming Autism Ltd | Health & social care | 2024 |
| Afghanpure Limited | Wholesale & retail | 2022 |
| Afia Commercial Consultants Limited | Financial services | 2020 |
| AFP Property Limited | Real estate | 2016 |
| Africa Golf Foundation Ltd | Arts & recreation | 2024 |
| African Dreams International Limited | Health & social care | 2013 |
| African Sun Limited | Other services | 2010 |
| Afriqe Ltd | Wholesale & retail | 2025 |
| After. Life Arrangements Limited | Other services | 2019 |
| AFX Investments Ltd | Real estate | 2023 |
| AG Communications Ltd | Extraterritorial | 2025 |
| AG Impact Ltd | Professional & scientific | 2010 |
| AG Platinum Ltd | Wholesale & retail | 2023 |
| Agendum (UK) Ltd | Health & social care | 2005 |
| Agile Beans Limited | Information & communication | 2024 |