| Accurate Envelope Testing Ltd | Information & communication | 2025 |
| Ace Autos Bedford Ltd | Wholesale & retail | 2025 |
| Ace Builders (Flamstead) Limited | Construction | 2010 |
| Ace Cars (Bedford) Limited | Extraterritorial | 2013 |
| Ace Education Consultancy Ltd | Education | 2016 |
| Ace Fire & Security Systems Ltd | Administrative & support | 1996 |
| Ace Fleet Maintenance Ltd | Manufacturing | 2015 |
| Ace Gutter Services Ltd | Administrative & support | 2023 |
| Ace High Media Limited | Professional & scientific | 2025 |
| Ace Resin Flooring Ltd | Construction | 2018 |
| Ace Sourcing Solutions Limited | Wholesale & retail | 2018 |
| Ace Today Ltd | Real estate | 2011 |
| Ace's Machines Ltd | Arts & recreation | 2026 |
| Aces Property Investments Ltd | Real estate | 2020 |
| ACH Technical Ltd | Manufacturing | 2023 |
| Achievegood Ltd | Professional & scientific | 2010 |
| Acies Insight Limited | Professional & scientific | 2024 |
| Acisu Limited | Hospitality | 2018 |
| Ackee Limited | Hospitality | 2006 |
| ACL Collective CIC | Arts & recreation | 2024 |
| ACL Consultants UK Limited | Financial services | 2025 |
| ACL Electrical Contractors Limited | Construction | 2012 |
| ACM Properties Limited | Real estate | 2003 |
| Acmbedfordmotors Limited | Wholesale & retail | 2017 |
| ACO Contractors Ltd | Construction | 2019 |
| Acorn Communication Consultancy Limited | Professional & scientific | 2007 |
| Acorn Mews Management Company Limited | Households | 1987 |
| Acrew Holdings Limited | Financial services | 2018 |
| Acrew Limited | Other services | 2015 |
| Acro's Collectables Ltd | Wholesale & retail | 2025 |
| Acrobridge Properties Limited | Real estate | 1986 |
| Acropolis DRS Limited | Administrative & support | 2022 |
| Acropolis Mini Market Ltd | Wholesale & retail | 2025 |
| Acropolis Property Investments Limited | Real estate | 2017 |
| Acruk Ltd | Wholesale & retail | 2023 |
| Acsoft Holdings Limited | Professional & scientific | 2011 |
| Acsoft Limited | Professional & scientific | 1993 |
| Action Maths Limited | Education | 2020 |
| Action on Gilbert's Syndrome | Health & social care | 2003 |
| Action Tees Group Limited | Wholesale & retail | 2024 |
| Actioneager Projects Limited | Financial services | 1992 |
| Actiontek Limited | Construction | 2018 |
| Active Play Installations Ltd | Construction | 2023 |
| Active Posture Limited | Wholesale & retail | 2018 |
| Activrehab Ltd | Health & social care | 2026 |
| Actondain Limited | Construction | 1988 |
| Actualise Consultancy Services Ltd | Professional & scientific | 2015 |
| Acuigen Europe Limited | Information & communication | 2020 |
| Acuitas REG Limited | Professional & scientific | 2026 |
| Acunovo IT Ltd | Wholesale & retail | 2011 |
| Aczafi Ltd | Transport & logistics | 2022 |
| AD Aesthetics Ltd | Health & social care | 2020 |
| AD Blue R US Ltd | Wholesale & retail | 2024 |
| AD Media Relations Limited | Professional & scientific | 2015 |
| AD Recordings Limited | Information & communication | 2009 |
| Ad-Ditive Biogas Products Limited | Wholesale & retail | 2020 |
| AD7 Properties Ltd | Real estate | 2018 |
| ADA and Alan Limited | Information & communication | 2019 |
| ADA Cosmetics International Ltd | Wholesale & retail | 1993 |
| Adagiox Limited | Information & communication | 2026 |
| Adail Ltd | Professional & scientific | 2025 |
| Adalee Properties Limited | Real estate | 2022 |
| Adam Brett Property Ltd | Hospitality | 2023 |
| Adam Class 1 Ltd | Transport & logistics | 2017 |
| Adam Loveday Eyecare Ltd | Health & social care | 2014 |
| Adam Peaty Limited | Arts & recreation | 2014 |
| Adam Smith Catering Ltd | Hospitality | 2019 |
| Adam Tahir Wills Ltd | Professional & scientific | 2024 |
| Adam's Transport Ltd | Transport & logistics | 2025 |
| Adams Building Services Ltd | Construction | 2003 |
| Adams Place Management Company (NO 1) Limited | Real estate | 2000 |
| Adams Place Management Company (NO 2) Limited | Real estate | 2000 |
| Adams Place Management Company (NO.3) Limited | Households | 2003 |
| Adams Precious Ltd | Wholesale & retail | 2026 |
| Adamson’S Property Limited | Households | 2024 |
| Adarda Ltd | Real estate | 2025 |
| Adas Limited | Manufacturing | 1993 |
| Adch Ltd | Construction | 2026 |
| Addictive Properties Limited | Real estate | 2019 |
| Addison Accounts & Training Ltd | Professional & scientific | 2015 |
| Addison Cars Ltd | Wholesale & retail | 2019 |
| Addison Conveyancing Limited | Professional & scientific | 2023 |
| Addoc Health Care Ltd | Public administration | 2018 |
| Addoc Properties Ltd | Real estate | 2021 |
| Addoc Retail Ltd | Wholesale & retail | 2025 |
| Addvert Ltd | Professional & scientific | 2018 |
| Addys Chopz Ltd | Hospitality | 2021 |
| ADE - Daniel Enterprise Limited | Health & social care | 2025 |
| Adeditorial Ltd | Professional & scientific | 2013 |
| Adeet Medics Ltd | Health & social care | 2021 |
| Adelaide House Residents' Association Limited | Households | 1987 |
| Adele-Marie Ltd | Health & social care | 2022 |
| Adelle Moss Ltd | Arts & recreation | 2016 |
| Adelphus UK Ltd | Financial services | 2020 |
| Aden Contracting Limited | Construction | 2007 |
| ADG Sports Therapy Coaching Services Limited | Arts & recreation | 2026 |
| Adhas Care Ltd | Hospitality | 2023 |
| Adhrit Consultancy Ltd | Health & social care | 2020 |
| ADI Construction Services Ltd | Construction | 2023 |
| ADI Pharma Limited | Wholesale & retail | 2015 |