| Accent Maintenance Ltd | Construction | 2011 |
| Accent Publications Limited | Information & communication | 2015 |
| Accentbio Ltd | Professional & scientific | 2006 |
| Access Economics Ltd | Education | 2018 |
| Access Independent Ltd | Health & social care | 2003 |
| Access to Export (Cambridge) | | 1999 |
| Acclarogen Limited | Professional & scientific | 2009 |
| Accommodeep Ltd | Manufacturing | 2023 |
| Accompany AI Global Limited | Manufacturing | 2025 |
| Accordia Apartments Cambridge Limited | Hospitality | 2009 |
| Accordia Street Garden Limited | Households | 2004 |
| Accountants Plus - Cambridge Ltd | Professional & scientific | 2016 |
| Accounting Essentials (UK) Ltd | Information & communication | 2011 |
| Accountstaxplus Online Ltd | Administrative & support | 2013 |
| Accucal Ltd | Wholesale & retail | 2024 |
| Accumulate Wealth Management Group Limited | Financial services | 2015 |
| Accuvex Ltd | Information & communication | 2009 |
| ACD Estates Limited | Real estate | 2016 |
| Ace 3D Design Ltd | Professional & scientific | 2021 |
| Ace Cultural Tours Limited | Administrative & support | 2009 |
| Ace Electric Vehicle Co., Ltd | Extraterritorial | 2018 |
| Ace Meter Technology Co., Limited | Extraterritorial | 2019 |
| Ace Pools Ltd | Administrative & support | 2016 |
| Ace Tree Surgery and Landscaping Ltd | Administrative & support | 2025 |
| Ace Waves Ltd | Information & communication | 2026 |
| Acer Construction Consultants Ltd | Construction | 2020 |
| Aceso Biosciences Limited | Health & social care | 2022 |
| Acfoo Ltd | Professional & scientific | 2024 |
| Achall Ltd | Information & communication | 2012 |
| Achayans Choice Ltd | Wholesale & retail | 2020 |
| Achiles Aviation Maintenance Ltd | Manufacturing | 2024 |
| Achlor Global Ltd. | Wholesale & retail | 2024 |
| Achmedia Ltd | Administrative & support | 2010 |
| Acifx Ltd | Information & communication | 2025 |
| Aciobanitei Cristian Ltd | Manufacturing | 2025 |
| ACJ Orthotics Ltd | Health & social care | 2024 |
| Acker Coaching Ltd | Professional & scientific | 2022 |
| ACL Block Management Limited | Households | 2021 |
| Aclardian Limited | Wholesale & retail | 2008 |
| ACM Cambridge Ltd | Education | 2019 |
| ACM Clinical Limited | Health & social care | 2023 |
| ACM Engineer Ltd | Manufacturing | 2022 |
| Acme Anaesthetics Limited | Health & social care | 2025 |
| Acme Sawing Machines Ltd. | Wholesale & retail | 2005 |
| Acoilcen Ltd | Wholesale & retail | 2025 |
| Acorn Architectural Ironmongery Limited | Wholesale & retail | 2002 |
| Acorn Court Management Company Limited | Real estate | 2010 |
| Acorn Property Improvements Limited | Construction | 2025 |
| Acoustical Control Consultants Limited | Professional & scientific | 1981 |
| ACP Investments Limited | Real estate | 2023 |
| Acquisan Limited | Financial services | 2024 |
| Acratech Limited | Construction | 2002 |
| Acrecrest Properties Limited | Real estate | 1998 |
| Acresis UK Limited | Professional & scientific | 2015 |
| Acria DX Ltd | Professional & scientific | 2023 |
| Acroma Home Ltd | Wholesale & retail | 2024 |
| Acropolis Audio Ltd | Manufacturing | 2018 |
| Acsis Property Ltd | Real estate | 2024 |
| ACT Flooring Consultancy Limited | Professional & scientific | 2019 |
| Acteon Communication and Learning Limited | Extraterritorial | 2012 |
| Actigen Limited | Professional & scientific | 1997 |
| Action for Children's Arts | Arts & recreation | 1999 |
| Action Rocket Ltd | Professional & scientific | 2011 |
| Activ Insulation Ltd | Construction | 2020 |
| Activate Pilates Limited | Arts & recreation | 2008 |
| Active Together CIC | Health & social care | 2026 |
| Activotec Limited | Professional & scientific | 2010 |
| Actiwise Limited | Administrative & support | 2009 |
| Actmask Group Co., Ltd | Extraterritorial | 2013 |
| Actualise Consulting Limited | Information & communication | 2014 |
| Acucert Limited | Construction | 2020 |
| Acucert Training Ltd | Education | 2020 |
| Acumen Compliance Consultant Ltd | Professional & scientific | 2026 |
| Acura Medical Consulting Ltd | Professional & scientific | 2023 |
| Acute Medicine East Anglia Limited | Manufacturing | 2009 |
| ACW Associates Limited | Professional & scientific | 2018 |
| ACX Instruments Ltd | Professional & scientific | 2022 |
| ACX Therapeutics Limited | Administrative & support | 2024 |
| ACZ Composites Ltd | Manufacturing | 2018 |
| AD Astra Medical Consultancy Limited | Health & social care | 2018 |
| AD Consulting Engineers Ltd | Professional & scientific | 2021 |
| AD Futura Ltd | Administrative & support | 2018 |
| AD Locum Services Ltd | Health & social care | 2015 |
| AD LUX Living Limited | Real estate | 2026 |
| ADA Card Limited | Wholesale & retail | 2022 |
| ADA Food and Beverage Ltd | Manufacturing | 2024 |
| ADA Global Industrial Co., Ltd | Information & communication | 2014 |
| Ada's Kitchen Cambridge Ltd | Hospitality | 2025 |
| Adam and EVE Court Cambridge Limited | Real estate | 1998 |
| Adam Cabs Ltd | Transport & logistics | 2018 |
| Adam Consulting Co. Limited | Information & communication | 2019 |
| Adam James Willett Limited | Extraterritorial | 2024 |
| Adam Kirby Racing Limited | Arts & recreation | 2012 |
| Adam Kitchen Limited | Hospitality | 2025 |
| Adam Lewis Tree Surgery Ltd | Administrative & support | 2020 |
| Adamant Composites UK Ltd | Professional & scientific | 2023 |
| Adams & Newman Ltd | Construction | 2006 |
| Adamson Develop and Build Limited | Real estate | 1997 |
| Adamson Property Investment Limited | Real estate | 2017 |
| Adamwear Ltd | Wholesale & retail | 2025 |