| Adscreen Support Services Ltd | Administrative & support | 2023 |
| Adstory Ltd | Professional & scientific | 2021 |
| Advaland Farming Company Limited | Professional & scientific | 1997 |
| Advaland Limited | Construction | 1996 |
| Advance Approval Consultancy Services Ltd | Professional & scientific | 2003 |
| Advance Biotech Ltd | Administrative & support | 2017 |
| Advance Tech Solutions Limited | Construction | 2011 |
| Advance Vehicle Rental Limited | Administrative & support | 2003 |
| Advanced Aesthetics NON Surgical Solutions Ltd | Other services | 2016 |
| Advanced Car Sales Ltd | Wholesale & retail | 2024 |
| Advanced Cladding Solutions Ltd | Construction | 2011 |
| Advanced Clinical Academy Limited | Education | 2025 |
| Advanced Commercial Properties Ltd | Real estate | 2023 |
| Advanced Controls & Management Systems Limited | Administrative & support | 2002 |
| Advanced Joinery (East) Limited | Construction | 2014 |
| Advanced Metalcraft Limited | Manufacturing | 2012 |
| Advanced Property and Holdings Ltd | Construction | 2021 |
| Advanced Rent Limited | Financial services | 2011 |
| Advanced Repair Solutions Ltd | Wholesale & retail | 2019 |
| Advanced Research Associates Limited | Real estate | 2003 |
| Advanced Services Ltd | Professional & scientific | 2016 |
| Advantage Rugby Academy Ltd | Arts & recreation | 2026 |
| Advent Facilities Management Ltd | Wholesale & retail | 2011 |
| Advent FM Ltd | Wholesale & retail | 2011 |
| Advent Rooflines Limited | Construction | 2005 |
| Adventure NO. 1 Limited | Professional & scientific | 2017 |
| Advert Holdings Ltd | Extraterritorial | 2021 |
| Adverweb 57 Ltd | Wholesale & retail | 2013 |
| Adviqo UK Limited | Information & communication | 1997 |
| Advisory Holdings Ltd | Extraterritorial | 2022 |
| ADW Industry Services Ltd | Transport & logistics | 2016 |
| Adya Ltd | Health & social care | 2021 |
| AE Cosmetics Limited | Wholesale & retail | 2015 |
| AE Creative Media Limited | Professional & scientific | 2023 |
| AE GEO Integrated Services Ltd | Professional & scientific | 2025 |
| AE Motors Birmingham Ltd | Wholesale & retail | 2017 |
| AEG 74 Limited | Real estate | 2025 |
| AEI Holdco Limited | Energy | 2013 |
| AEI Lending Limited | Energy | 2013 |
| AEI Solar Limited | Energy | 2013 |
| AEJ Trading Limited | Financial services | 2025 |
| AEL (Garlogie) Limited | Financial services | 2025 |
| Aeon Flux and Co. Ltd | Professional & scientific | 2026 |
| Aeon Web Limited | Information & communication | 2009 |
| Aera Active Ltd | Wholesale & retail | 2026 |
| Aero Contracts Limited | Manufacturing | 2025 |
| Aero Standard Limited | Manufacturing | 2025 |
| Aerolite Garage Limited | Wholesale & retail | 2004 |
| Aeromario Ltd | Manufacturing | 2016 |
| Aerospace Graphics Ltd | Professional & scientific | 2022 |
| Aerotech Maintenance Ltd | Transport & logistics | 2023 |
| Aesir Transport Solutions Ltd | Transport & logistics | 2025 |
| Aesop Ventures Limited | Administrative & support | 2011 |
| Aesthetic Room (Norfolk) Ltd | Administrative & support | 2021 |
| Aesthetics by Hannah Ltd | Other services | 2025 |
| Aesthetics by Ricci Jade Ltd | Other services | 2025 |
| Aesthetics by Taryn Ltd | Other services | 2021 |
| Aeys Associates (UK) Ltd | Professional & scientific | 2015 |
| AF Affinity Limited | Other services | 1980 |
| AF Consulting UK Limited | Information & communication | 2005 |
| AF Renewable Ltd | Construction | 2022 |
| AF Solutions Ltd | Wholesale & retail | 2026 |
| AF Stories Limited | Other services | 2019 |
| Afamefuna Ltd | Health & social care | 2020 |
| Afbb Limited | Health & social care | 2017 |
| AFD Consultancy Limited | Manufacturing | 2025 |
| AFF Edtech Ltd | Professional & scientific | 2017 |
| Affinity (EA) Management Company Limited | Households | 2006 |
| Affinity Care Advisory Ltd | Professional & scientific | 2024 |
| Affinity Care Recruitment Services Ltd | Professional & scientific | 2024 |
| Affinity Care Training Ltd | Professional & scientific | 2024 |
| Affinity Group Holdings Limited | Information & communication | 2017 |
| Affinity Group Limited | Administrative & support | 2004 |
| Affirmed Outcomes Limited | Professional & scientific | 2010 |
| Affordable Vehicle Movements Ltd | Transport & logistics | 2020 |
| AFG Food Ltd | Hospitality | 2025 |
| Afonaz Limited | Hospitality | 2020 |
| Afongan Ltd | Professional & scientific | 2013 |
| African Mantra Limited | Real estate | 2022 |
| Afrikana Cardiff Ltd | Wholesale & retail | 2019 |
| Afrolingua Ltd | Education | 2025 |
| Afrotrader Limited | Wholesale & retail | 2024 |
| AFS Energy Limited | Real estate | 2026 |
| AFS Holdings Ltd | Professional & scientific | 2018 |
| After Dark Promotions Ltd | Arts & recreation | 2019 |
| AG Technology Solutions Ltd | Information & communication | 2020 |
| AGA TAN and Beauty Ltd | Other services | 2024 |
| Agamarama Ltd | Professional & scientific | 2019 |
| Agbonlamoore Music Ltd | Information & communication | 2021 |
| AGC and Kids Limited | Health & social care | 2015 |
| AGE Concern Norfolk | Information & communication | 1999 |
| AGE Safe Ltd | Health & social care | 2024 |
| AGE UK Norwich (Services) Limited | Health & social care | 2000 |
| AGE UK Norwich Limited | Health & social care | 2002 |
| Agency Express Limited | Administrative & support | 1998 |
| Agency Ltd | Information & communication | 2020 |
| Agentzero Energy Limited | Information & communication | 2026 |
| Aggregators UK Limited | Professional & scientific | 2011 |
| AGI Consulting Ltd | Education | 2023 |
| Agile Affinity LLP | | 2019 |