| Abdelrahman Holdings Limited | Real estate | 2017 |
| Aberaeron Conservation Limited | Real estate | 2022 |
| Aberdeen Financial Limited | Financial services | 2009 |
| Abergavenny 3-PEAK Properties Ltd | Hospitality | 2022 |
| ABK Barbers Ltd | Other services | 2020 |
| ABK Capital Holdings Limited | Financial services | 2025 |
| Ablou Facilities Ltd | Administrative & support | 2018 |
| Abode & Co SW Ltd | Construction | 2025 |
| Abode Heat Limited | Professional & scientific | 2018 |
| Aboulton Consultancy Ltd | Professional & scientific | 2025 |
| About the House Limited | Construction | 1997 |
| Above the Fold Limited | Information & communication | 2021 |
| ABP 1 Limited | Real estate | 2021 |
| ABR Financial Solutions Ltd | Professional & scientific | 2025 |
| Absolute Care Group Ltd | Health & social care | 2023 |
| Absolute PR and Marketing Limited | Professional & scientific | 2014 |
| Absolute PR and Marketing Trustees Limited | Professional & scientific | 2023 |
| Absolutedogs Ltd | Information & communication | 2014 |
| Absolutely Knot Ltd | Manufacturing | 2023 |
| Absolutely Mintage Limited | Wholesale & retail | 2017 |
| AC Archaeology and Heritage Ltd | Professional & scientific | 2008 |
| AC Community Homes Ltd | Financial services | 2026 |
| AC Developments (Torquay) Ltd | Financial services | 2026 |
| AC Property Maintenance (South West) Ltd | Construction | 2015 |
| Acacia Analysis Limited | Professional & scientific | 2024 |
| Academy of Floral Art Limited | Education | 2013 |
| Academy of Music & Sound (Gateshead) Ltd | Education | 2009 |
| Academy of Music & Sound (Holdings) Limited | Financial services | 2021 |
| Academy of Music & Sound (Online) Ltd | Education | 2025 |
| Academy of Music & Sound (UK) Ltd | Education | 2011 |
| Academy of Music & Sound Ltd | Education | 2002 |
| Access 28 Limited | Construction | 2024 |
| Access and Building Consultancy Limited | Professional & scientific | 2015 |
| Accessible Vehicle Conversions CIC | Manufacturing | 2018 |
| Accipetex System Ltd | Health & social care | 2023 |
| Accogem Ltd | Real estate | 2023 |
| Account & Tax Ability Limited | Professional & scientific | 1997 |
| Accountancy Learning Distance Learning Ltd | Education | 2001 |
| Accountancy Learning Innovations Ltd | Education | 2010 |
| Accountancy Learning Ltd | Education | 1997 |
| Accountancy Solutions (Exeter) Limited | Professional & scientific | 2022 |
| Accountants Inc. (UK) Ltd | Professional & scientific | 2021 |
| Accountants Inc. Ltd | Professional & scientific | 2019 |
| Accs Consulting Ltd | Information & communication | 2015 |
| Accutech Limited | Health & social care | 2013 |
| Ace Construction (SW) Ltd | Construction | 2023 |
| Ace Enabling Services Ltd | Health & social care | 2019 |
| Ace Incorporated Limited | Real estate | 2020 |
| Ace Plumbing & Heating South West Ltd | Construction | 2021 |
| Ace Residential Estates Limited | Real estate | 2023 |
| Ace SPV Ltd | Real estate | 2024 |
| Acekeen Limited | Administrative & support | 1986 |
| Acer Investments 2025 Limited | Financial services | 2025 |
| Acer Landscapes & Paving Limited | Administrative & support | 2003 |
| Acfpv Ltd | Professional & scientific | 2025 |
| Achievers in Life Ltd | Other services | 2014 |
| Achilles Lifestyle Ltd | Health & social care | 2025 |
| Acid Properties Limited | Real estate | 2021 |
| Ackland Hill Papenfus Solicitors Limited | Professional & scientific | 2012 |
| ACL Structures Limited | Construction | 1983 |
| ACM Car Sales Ltd | Wholesale & retail | 2022 |
| Acoometi Premier Services Limited | Information & communication | 2008 |
| Acorn Site Solutions Ltd | Construction | 2026 |
| Acorn to Oak Joyful Beginnings CIC | Health & social care | 2026 |
| Acousti-Clad (Interiors) Limited | Construction | 1991 |
| Acoustic Associates South West Ltd | Professional & scientific | 1991 |
| Acros KR Limited | Hospitality | 2025 |
| Actdec Limited | Education | 2008 |
| Action BI Ltd | Information & communication | 2015 |
| Active Electronics (Holdings) Limited | Wholesale & retail | 2018 |
| Active Sportswear Limited | Transport & logistics | 1986 |
| Activities to Share Ltd | Wholesale & retail | 2010 |
| Actp Construction Limited | Real estate | 2020 |
| Actura Advisory Limited | Professional & scientific | 2026 |
| Acuma Limited | Financial services | 2001 |
| Acura T&T Ltd | Transport & logistics | 2016 |
| AD Property (SW) Ltd | Real estate | 2024 |
| Adam Gray Projects Ltd | Administrative & support | 2013 |
| Adam Turner Properties Ltd | Real estate | 2021 |
| Adamas Living Ltd | Administrative & support | 2025 |
| Adams Business Finance LLP | | 2009 |
| Adamski Design Ltd | Professional & scientific | 2024 |
| Adapt Archive Ltd | Wholesale & retail | 2024 |
| Adaptive Property Group Limited | Real estate | 2019 |
| ADD Air Media Ltd | Information & communication | 2018 |
| Addicott Electrics Limited | Manufacturing | 1987 |
| Addington Farm Limited | Construction | 2022 |
| Addison Anne UK Holdings Limited | Information & communication | 2019 |
| Additions & Subtractions Limited | Professional & scientific | 1998 |
| Additive Music PR Ltd. | Arts & recreation | 2016 |
| Addo Greendale Limited | Other services | 2025 |
| Addo Pinhoe Ltd | Administrative & support | 2020 |
| Adele Stickland Wellbeing Consultant Ltd | Professional & scientific | 2017 |
| Adeola Elizabeth Funsho-Ako Ltd | Wholesale & retail | 2019 |
| Adept Consultancy UK Limited | Professional & scientific | 2009 |
| Adeptio Ltd | Professional & scientific | 2018 |
| Adeptus Certification and Inspections UK Limited | Professional & scientific | 2017 |
| Adeshal PVT Ltd | Hospitality | 2025 |
| Adhdsd Ltd | Information & communication | 2018 |
| ADL2 Development Limited | Construction | 2019 |