| Abbey Records Limited | Information & communication | 2012 |
| Abbi Financial Limited | Financial services | 2018 |
| Abbott Management Limited | Real estate | 1993 |
| ABC College UK Limited | Education | 2002 |
| ABC Constructions Ltd | Construction | 2008 |
| Abcplumbing Ltd | Construction | 2025 |
| Abdiaj Construction Ltd | Construction | 2019 |
| Abdiaj Properties Ltd | Real estate | 2023 |
| Abdur Rahim Limited | Financial services | 2018 |
| Aberdeen Land Investments Ltd | Professional & scientific | 2011 |
| Abilo London Ltd | Manufacturing | 2019 |
| Abingdon Lodge (Barnet) Co. Limited | Households | 1995 |
| Abington Flat Management Company Limited | Households | 1983 |
| Able Internet Limited | Information & communication | 2020 |
| Able Partners Ltd | Financial services | 2025 |
| ABO Enterprise Limited | Health & social care | 2017 |
| Abode Collective Ltd | Administrative & support | 2025 |
| Abode Wellness Ltd | Arts & recreation | 2024 |
| ABS Manor Ltd | Professional & scientific | 2025 |
| Absolute Glazing and Services Ltd | Construction | 2016 |
| Absolute Internet Limited | Information & communication | 2021 |
| Absolutebalance Limited | Health & social care | 2006 |
| Absolutelander Ltd | Construction | 2017 |
| Absolutely Amazingly Awesome Gaming Hardcore Heroes Ltd | Information & communication | 2026 |
| Absolutely Barking Limited | Hospitality | 1997 |
| ABT Trust Limited | Financial services | 2021 |
| ABX Trading Ltd | Wholesale & retail | 2025 |
| AC Finchley C.I.C. | Arts & recreation | 2007 |
| AC Growth Limited | Wholesale & retail | 2017 |
| AC Parl Street Buyers Ltd | Real estate | 2016 |
| ACA Property Holdings Ltd | Financial services | 2023 |
| Accelerate PR Ltd | Professional & scientific | 2013 |
| Acceleratrix Limited | Information & communication | 2013 |
| Accendo Holdings Ltd | Financial services | 2015 |
| Accendo Markets Limited | Financial services | 2007 |
| Access Bridging Finance Limited | Financial services | 2006 |
| Access Business Services Ltd | Real estate | 1995 |
| Accommodation Road Management Company Limited | Real estate | 2021 |
| Accountancy & Financial Services (UK) Ltd | Professional & scientific | 2002 |
| Accountancy Zone Limited | Professional & scientific | 2014 |
| Accounts EYE Ltd | Professional & scientific | 2026 |
| Accounts Realtime Ltd | Hospitality | 2016 |
| Accumulate Wealth Management (Kent) Ltd | Financial services | 2013 |
| Ace Beverage Company London Limited | Hospitality | 2015 |
| Ace Collection Limited | Real estate | 2026 |
| Ace Promotion Ltd | Wholesale & retail | 2017 |
| Ace Suites Ltd | Hospitality | 2019 |
| Aced Management Ltd | Administrative & support | 2022 |
| Achdut JRT Ltd | Professional & scientific | 2020 |
| Acinni Ltd | Real estate | 2015 |
| ACK Electrical Wholesale Limited | Wholesale & retail | 2017 |
| Ackmz Investments Ltd | Real estate | 2023 |
| Acorn Creative Print Ltd | Manufacturing | 2019 |
| Acoustic Management Solutions Ltd | Professional & scientific | 2024 |
| Acre Bierton Ltd | Real estate | 2021 |
| Acre Birch Green Ltd | Real estate | 2025 |
| Acre Bucks Hill Ltd | Real estate | 2024 |
| Acre Bushey Ltd | Real estate | 2025 |
| Acre Chiswell Limited | Real estate | 2021 |
| Acre Cottered Ltd | Real estate | 2026 |
| Acre DHR Limited | Real estate | 2025 |
| Acre DHR Phase 3 Ltd | Real estate | 2026 |
| Acre Elle Dani Limited | Real estate | 2022 |
| Acre Elstree Ltd | Real estate | 2026 |
| Acre Epping Ltd | Real estate | 2023 |
| Acre Great Ltd | Real estate | 2026 |
| Acre Haddenham Ltd | Real estate | 2025 |
| Acre Hertfordshire Limited | Real estate | 2024 |
| Acre Lane Assets Limited | Construction | 2017 |
| Acre Leighton Buzzard Limited | Real estate | 2025 |
| Acre London Group Ltd | Financial services | 2022 |
| Acre London Holdings Ltd | Real estate | 2024 |
| Acre London Projects Ltd | Construction | 2020 |
| Acre London Ventures Ltd | Real estate | 2024 |
| Acre Raybrook Limited | Real estate | 2026 |
| Acre RH Ltd | Real estate | 2026 |
| Acre SA Ltd | Real estate | 2025 |
| Acre Shenley Hill Ltd | Real estate | 2022 |
| Acre Slough (Phase 2) Ltd | Real estate | 2026 |
| Acre Slough Limited | Real estate | 2025 |
| Acre ST Albans Ltd | Real estate | 2023 |
| Acre ST Albans Management Ltd | Real estate | 2024 |
| Acre Stevenage Ltd | Real estate | 2023 |
| Acre Stoke Poges Limited | Real estate | 2024 |
| Acre Watford DEV Co Ltd | Real estate | 2023 |
| Acre Winchmore Hill Ltd | Real estate | 2025 |
| Acre Wycombe 2 Ltd | Real estate | 2025 |
| Acreplan Finance Ltd | Financial services | 2016 |
| Acreplan Limited | Construction | 2013 |
| Acreplan Sylvester ST Developments Ltd | Construction | 2016 |
| ACS Homecare Ltd | Health & social care | 2019 |
| ACT Consultancy (UK) Limited | Administrative & support | 2022 |
| ACT Cool Records Ltd | Manufacturing | 2022 |
| Actaris Recruitment Limited | Administrative & support | 2013 |
| Actaris Site Services Limited | Administrative & support | 2017 |
| Actega Schmid Rhyner AG Limited | Transport & logistics | 2024 |
| Action Home Improvements Limited | Construction | 2009 |
| Action Shots Limited | Information & communication | 2011 |
| Activate Fire and Security Ltd | Administrative & support | 2018 |
| Active Magazines Limited | Professional & scientific | 2004 |