| Abtek Automotive Ltd. | Wholesale & retail | 2020 |
| Abuleis Properties Ltd | Real estate | 2025 |
| Abundance & Health Europe LLP | | 2013 |
| Abundant Universe Limited | Education | 2023 |
| Abury Limited | Construction | 2017 |
| ABW Ltd | Information & communication | 2024 |
| Abyem Investment Ltd | Real estate | 2023 |
| AC Advisory Services Ltd | Real estate | 2025 |
| AC Aesthetic Services Limited | Health & social care | 2020 |
| AC Construction & Consultants Ltd | Professional & scientific | 2025 |
| AC Family Law Limited | Professional & scientific | 2021 |
| AC Investco Ltd | Financial services | 2022 |
| AC Plumbing & Heating Specialists Ltd | Construction | 2011 |
| AC Recovery Ltd | Transport & logistics | 2026 |
| AC Wholesale Services Limited | Wholesale & retail | 2017 |
| Acacia Villas Freeholders Limited | Households | 1999 |
| Academy Holland Park Ltd | Real estate | 2017 |
| Academy of Modern Tantra Ltd | Education | 2021 |
| Acaj Ltd | Other services | 2008 |
| Acamedics Ltd | Education | 2012 |
| Acas Management Ltd | Construction | 2019 |
| ACC Logistics Ltd | Transport & logistics | 2024 |
| Accelerate Digital Consulting Limited | Information & communication | 2020 |
| Accelerated Business Development Ltd | Professional & scientific | 2025 |
| Accelerated Payments UK Limited | Other services | 2019 |
| Accelix Digital Ltd | Information & communication | 2025 |
| Accent Construction Ltd | Construction | 2021 |
| Accentuate Yourself Limited | Administrative & support | 2018 |
| Acces Link Ltd | Construction | 2018 |
| Access Estate Planning Limited | Administrative & support | 2021 |
| Access Financial Partnership Ltd | Administrative & support | 2021 |
| Access Financial Services Limited | Financial services | 2002 |
| Access Link Group Limited | Construction | 2023 |
| Access Solutions (EVACU8) Limited | Administrative & support | 2024 |
| Access Wealth Limited | Real estate | 2017 |
| ACCESS24 Healthcare Ltd | Hospitality | 2013 |
| Accessible Insurance Services Ltd | Financial services | 2021 |
| Acceszibles Limited | Professional & scientific | 2019 |
| Acclaim Care Agency Limited | Public administration | 2023 |
| Acclaim Properties Ltd | Real estate | 2023 |
| Accommodo UK Limited | Administrative & support | 2023 |
| Accord Family Law Limited | Professional & scientific | 2015 |
| Accord Risk Limited | Extraterritorial | 2025 |
| Accordance Care Services Limited | Administrative & support | 2024 |
| Accordis Global Limited | Administrative & support | 2026 |
| Account Office Ltd | Extraterritorial | 2013 |
| Accountability Brown + Co. Limited | Professional & scientific | 2009 |
| Accountancy Logix Limited | Professional & scientific | 2025 |
| Accountants Milton Keynes Ltd | Professional & scientific | 2023 |
| Accounting & Business Consultancy Limited | Extraterritorial | 1999 |
| Accounting Holding Ltd | Financial services | 2024 |
| Accounting MK Limited | Professional & scientific | 2007 |
| Accumulation Consulting Limited | Professional & scientific | 2024 |
| Accupulse Ltd | Professional & scientific | 2024 |
| Accura Imaging Limited | Manufacturing | 1992 |
| Accuris Global Limited | Financial services | 2023 |
| Accurite Solutions Ltd | Information & communication | 2026 |
| Accutax and Audit Ltd | Professional & scientific | 2024 |
| ACD Trading Ltd | Wholesale & retail | 2025 |
| Ace Accounts & Tax Limited | Professional & scientific | 2001 |
| Ace Business Finance Limited | Financial services | 2021 |
| Ace Care Consult Ltd | Health & social care | 2021 |
| Ace Cosgrove Limited | Real estate | 2015 |
| Ace Driving School Ltd | Education | 2022 |
| Ace Furtho Limited | Real estate | 2015 |
| Ace Link Solutions Ltd | Administrative & support | 2010 |
| Ace Property Collective Ltd | Real estate | 2026 |
| Ace Winner Limited | Information & communication | 2010 |
| Aceban Ltd | Information & communication | 2014 |
| Acepark Development Limited | Construction | 2011 |
| Acepubs Ltd | Hospitality | 2025 |
| Acepubs Opco Ltd | Hospitality | 2026 |
| Acerbis UK Limited | Manufacturing | 2007 |
| Aces Global Quality Services UK Limited | Professional & scientific | 2020 |
| Acesa Ltd | Education | 2025 |
| Acewashing Limited | Administrative & support | 2011 |
| ACG Decors Limited | Hospitality | 2024 |
| ACH Planning Limited | Professional & scientific | 2015 |
| Achievecleaning Ltd | Administrative & support | 2026 |
| Achievers Healthcare Limited | Administrative & support | 2022 |
| Achipa Limited | Health & social care | 2018 |
| Acies Medical Techology Limited | Manufacturing | 2025 |
| ACK Enterprises Ltd | Manufacturing | 2006 |
| Acksion Ltd | Professional & scientific | 2026 |
| Acland Road Limited | Construction | 2020 |
| ACM Traffic Support Services Limited | Transport & logistics | 1994 |
| Acmechanical Limited | Construction | 2026 |
| ACN Tool Ltd | Wholesale & retail | 2025 |
| ACO Sports Ltd | Education | 2025 |
| Acorai Limited | Professional & scientific | 2022 |
| Acorn (MK) Nurseries Limited | Wholesale & retail | 2013 |
| Acorn Building Service (MK) Ltd | Construction | 2018 |
| Acorn Capital Ltd | Financial services | 2012 |
| Acorn Conveyor Systems Limited | | 1980 |
| Acorn Day Nursery Limited | Education | 1993 |
| Acorn Early Years Foundation | Education | 2011 |
| Acorn Investment Management Limited | Other services | 2021 |
| Acorn Nursery Properties Limited | Real estate | 1990 |
| Acorn Peach Energy Ltd. | Energy | 2016 |
| Acorn Tuition Ltd | Education | 2026 |