| Abbexa Investments Ltd | Real estate | 2019 |
| Abbexa Laboratories Ltd | Professional & scientific | 2020 |
| Abbexa Ltd | Professional & scientific | 2013 |
| Abbey Court (Cambridge) Freehold Limited | Households | 2019 |
| Abbey Design Consultants Ltd | Information & communication | 2004 |
| Abbey DLD Colleges Limited | Education | 2022 |
| Abbey Garages (Cambridge) Limited | Real estate | 1984 |
| Abbey Park Thorney Residents Management Company Limited | Households | 2019 |
| Abbey Quay Estate Management Company Limited | Real estate | 2021 |
| Abbey Quay North Block Management Company Limited | Real estate | 2021 |
| Abbey Quay South Block Management Company Limited | Real estate | 2021 |
| Abbey Vale Limited | Other services | 2022 |
| Abbey Walk (Swineshead) Management Company Limited | Households | 2017 |
| Abbeygate Group Ltd | Transport & logistics | 2025 |
| Abbeygates Limited | Construction | 2007 |
| Abbinante & Sons Ltd | Construction | 2025 |
| Abbot's PVT Ltd | Administrative & support | 2025 |
| Abbotts Court Management Limited | Real estate | 1991 |
| ABC Bar-B-Q Limited | Hospitality | 2019 |
| ABC BBQ Grill Limited | Hospitality | 2024 |
| ABC Ltd | Extraterritorial | 2021 |
| ABC Plumbing and Maintenance Ltd | Construction | 2024 |
| ABC Power Trading Limited | Wholesale & retail | 2025 |
| Abcam (US) Ltd | Financial services | 2012 |
| Abcam Limited | Manufacturing | 1998 |
| Abcd Dermatopathology Course Ltd. | Administrative & support | 2017 |
| Abctree Limited | Agriculture & fishing | 2017 |
| ABD Building Services Limited | Construction | 2014 |
| Abdelhak Limited | Health & social care | 2024 |
| Abdellah's Limited | Health & social care | 2023 |
| Abdulaziz Saad Ltd | Professional & scientific | 2025 |
| Abelana Ltd | Arts & recreation | 2012 |
| Abelau Holdings Limited | Financial services | 2023 |
| Abelau Investments Limited | Real estate | 2016 |
| Abelau Limited | Information & communication | 2010 |
| Abery Dwellings Limited | Real estate | 2016 |
| ABG Automation Tech. Co., Ltd | Extraterritorial | 2016 |
| Abhariivitha Enterprises Limited | Wholesale & retail | 2026 |
| Abhi Real Estate Limited | Real estate | 2017 |
| Abhijeet Saxena Limited | Health & social care | 2019 |
| Abigail Molly Ltd | Wholesale & retail | 2025 |
| Abilia Ltd | Manufacturing | 1973 |
| Ability Resourcing Limited | Administrative & support | 2004 |
| Abinger Holdings Limited | Transport & logistics | 2025 |
| Abington Estate Management Limited | Households | 1985 |
| Abington LEA Ltd | Real estate | 2014 |
| Abington Park Limited | Construction | 1998 |
| Abington Sawmill Limited | Manufacturing | 2019 |
| Abington Woods CIC | Education | 2014 |
| Ablatimum Ltd | Construction | 2022 |
| Able Secure Ltd | Information & communication | 2022 |
| ABM Maintenance Ltd | Construction | 2002 |
| Abnoy Enterprises Ltd | Wholesale & retail | 2025 |
| Aboligo Limited | Professional & scientific | 2024 |
| About Sound Limited | Information & communication | 2009 |
| Above and Beyond Recruitment Ltd | Administrative & support | 2020 |
| ABR Flex Ltd | Transport & logistics | 2025 |
| Abracadabra Ltd | Professional & scientific | 2024 |
| Abrb Consulting Limited | Health & social care | 2025 |
| Abreiz Communication Ltd | Education | 2010 |
| Abrey Maintenance Ltd | Construction | 2015 |
| Abrish Co Ltd | Hospitality | 2024 |
| Abroad Room Ltd | Real estate | 2024 |
| Abscio Ltd | Information & communication | 2026 |
| Absolute Strategy Limited | Professional & scientific | 2006 |
| Absolute Strategy Research Limited | Financial services | 2006 |
| ABT International | | 2014 |
| ABT Systems Ltd | Information & communication | 2014 |
| Abubu Ltd | Wholesale & retail | 2026 |
| Abudist Decent Management Ltd | Information & communication | 2023 |
| Abzena (Cambridge) Limited | Professional & scientific | 2004 |
| Abzena (UK) Limited | Professional & scientific | 2001 |
| Abzena Limited | Professional & scientific | 2014 |
| Abzn Limited | Information & communication | 2025 |
| AC Electrical Cambridge Ltd | Construction | 2025 |
| AC Media Group Ltd | Other services | 2026 |
| AC Occupational Health (Cambridge) Limited | Health & social care | 2015 |
| AC Paint Ltd | Manufacturing | 2025 |
| AC Plumbing Ltd | Construction | 2019 |
| ACA Heating & Plumbing Limited | Construction | 2013 |
| ACA Research Ltd | Information & communication | 2017 |
| Acacia Capital Management Ltd | Households | 2017 |
| Acacia Court Management Co. Limited | Households | 1984 |
| Acaciadays Limited | Professional & scientific | 2025 |
| Acacias Holdings UK Ltd | Administrative & support | 2025 |
| Academic Oracle Ltd | Wholesale & retail | 2026 |
| Academico Ltd | Professional & scientific | 2020 |
| Academy of Critical Humanistic Studies Limited | Information & communication | 2025 |
| Academy of Nutritional Medicine Ltd | Professional & scientific | 2005 |
| Academy of Psychoanalysis | Education | 2004 |
| Acadia Limited | Information & communication | 2025 |
| Acapo Onsagers UK Ltd | Professional & scientific | 2023 |
| Acaso Ltd | Extraterritorial | 2009 |
| ACC Care Group Ltd | Public administration | 2025 |
| ACC Syndicate LLP | | 2021 |
| ACC Trade Ltd | Wholesale & retail | 2025 |
| Accelera Limited | Professional & scientific | 2018 |
| Acceleration Affiliates Ltd | Professional & scientific | 2024 |
| Acceleration Agency Ltd | Information & communication | 2023 |
| Accelerator Advisory Limited | Financial services | 2019 |