| Autotechnique Limited | Wholesale & retail | 2005 |
| Autotekz Cambridge Ltd | Wholesale & retail | 2024 |
| Autoware Foundation UK Limited | Information & communication | 2025 |
| Autozone (Newmarket) LLP | | 2020 |
| Auxergo Ltd | Professional & scientific | 2016 |
| Auxilium Angels Ltd | Health & social care | 2025 |
| Auxilium Care and Support Ltd | Health & social care | 2024 |
| AV Tools Ltd | Wholesale & retail | 2014 |
| AV8R Ltd | Professional & scientific | 2019 |
| Avadokya Ltd | Wholesale & retail | 2026 |
| Availl Limited | Health & social care | 2011 |
| Avalon Group Partnership LLP | | 2019 |
| Avalon Property Solutions Limited | Real estate | 2010 |
| Avamaker Ltd | Administrative & support | 2019 |
| Avan Vehicle Recovery Services Ltd | Transport & logistics | 2022 |
| Avanit Limited | Wholesale & retail | 2020 |
| Avant Education Limited | Education | 2022 |
| Avanti Tints Ltd | Wholesale & retail | 2021 |
| Avanti Traffic Management Limited | Administrative & support | 2010 |
| Avatrial Ltd | Professional & scientific | 2019 |
| Avay Properties Ltd | Real estate | 2023 |
| Avay Tech Ltd | Professional & scientific | 2024 |
| Avcabtec Ltd | Manufacturing | 2025 |
| Avcu Ltd | Professional & scientific | 2026 |
| Avdoc Ltd | Manufacturing | 2024 |
| Avelino Limited | Health & social care | 2015 |
| Avena Hill Limited | Information & communication | 2023 |
| Avenir Consultants Limited | Professional & scientific | 2002 |
| Avenor Group Ltd | Wholesale & retail | 2025 |
| Aventa Capital Partners Ltd | Financial services | 2011 |
| Aventis Consulting Group Ltd | Professional & scientific | 2025 |
| Avenue Farm Food Park Limited | Real estate | 2023 |
| Avenue Roofing Limited | Construction | 2024 |
| Avenzoar Consulting Ltd | Professional & scientific | 2019 |
| Average Bear Games Ltd | Manufacturing | 2026 |
| Averaq Ltd | Professional & scientific | 2024 |
| Aves Accounting Limited | Other services | 2020 |
| Aveva Finance Limited | Information & communication | 2013 |
| Aveva Financing Limited | Information & communication | 2019 |
| Aveva Group Limited | Manufacturing | 1994 |
| Aveva Limited | Information & communication | 2004 |
| Aveva Software GB Limited | Information & communication | 1998 |
| Aveva Solutions Limited | Information & communication | 1964 |
| AVI Harness Limited | Manufacturing | 2024 |
| Aviary House RTM Company Limited | Households | 2020 |
| Aviary Management (Tilehurst) Limited | Households | 1981 |
| Aviaschon Ltd | Manufacturing | 2018 |
| Aviatica Bloodstock Limited | Agriculture & fishing | 2020 |
| Aviatica Consulting Limited | Professional & scientific | 2003 |
| Aviatica Group Limited | Professional & scientific | 2020 |
| Aviation AV1 Ltd | Manufacturing | 2025 |
| Aviation DDD Ltd | Manufacturing | 2025 |
| Aviation Emissions Solutions Ltd | Transport & logistics | 2012 |
| Aviation ENG. Ltd | Manufacturing | 2026 |
| Aviation Engineering Services Limited | Manufacturing | 2023 |
| Aviation Maintenance Solutions Ltd | Manufacturing | 2024 |
| Aviation Nord Ltd | Manufacturing | 2026 |
| Aviation Painting Ltd | Manufacturing | 2025 |
| Aviation Surface Technology Paint & Quality Solutions Ltd | Manufacturing | 2021 |
| Aviation Technologies 33 Ltd | Manufacturing | 2024 |
| Aviationsnaomy Ltd | Manufacturing | 2025 |
| Aviatud Ltd | Manufacturing | 2024 |
| AVICIM05 Ltd | Manufacturing | 2026 |
| Aviconstrution Ltd | Construction | 2026 |
| Aviini Limited | Wholesale & retail | 2024 |
| Avio Kopter Ltd | Manufacturing | 2023 |
| Avio Maintenance Service Ltd | Manufacturing | 2025 |
| Avio Mara Ltd | Manufacturing | 2024 |
| Avio Technics International Ltd | Manufacturing | 2026 |
| Avional Ltd | Manufacturing | 2022 |
| Avionic Systems Ltd | Manufacturing | 2026 |
| Avionics Consulting Services Ltd | Manufacturing | 2026 |
| Avionics-Tech Ltd | Manufacturing | 2025 |
| Aviotech Services Ltd | Manufacturing | 2025 |
| Aviotech Solutions Ltd | Manufacturing | 2025 |
| Avito Limited | Information & communication | 2006 |
| Avlar Limited | Financial services | 1998 |
| Avlk Ltd | Real estate | 2016 |
| AVM Solutions Limited | Financial services | 2007 |
| AVM Training Ltd. | Administrative & support | 2021 |
| Avni & Aaron Ltd | Information & communication | 2011 |
| Avocet Cleaning Services Limited | Administrative & support | 2008 |
| Avocet FM Solutions Ltd | Professional & scientific | 2015 |
| Avolia Ltd | Wholesale & retail | 2025 |
| Avonmore Property Ltd | Financial services | 2020 |
| Avos Technology Ltd | Information & communication | 2022 |
| Avra Surgical Ltd | Health & social care | 2026 |
| Avrafa Ltd | Professional & scientific | 2023 |
| AW Radiology Limited | Health & social care | 2014 |
| AW Tax Limited | Professional & scientific | 2010 |
| Aw&C Investments Ltd | Administrative & support | 2000 |
| AWA Cambridge LLP | | 2021 |
| Awah Trading Co., Ltd | Wholesale & retail | 2023 |
| Awais Consulting Ltd | Information & communication | 2012 |
| Awaken Supplements Ltd | Manufacturing | 2023 |
| Award Associates Cambridge Limited | Professional & scientific | 2009 |
| Awesome Consulting Services Limited | Information & communication | 2017 |
| Awesome GUY Ltd | Manufacturing | 2025 |
| Awinyear Co., Ltd | Extraterritorial | 2020 |
| Awkward Silence Games Ltd | Information & communication | 2026 |