| Acreview Land Management Ltd | Administrative & support | 2026 |
| ACS Health Limited | Health & social care | 2022 |
| ACT Peer Recovery CIC | Other services | 2014 |
| Action Xtreme Ltd | Information & communication | 2019 |
| Adam ROY Ltd | Wholesale & retail | 2025 |
| Adaptpersonaltraining Ltd | Other services | 2025 |
| Adaya Management Limited | Professional & scientific | 2015 |
| Adefbtos Logistics Ltd | Agriculture & fishing | 2021 |
| Ademo Consulting Ltd | Professional & scientific | 2015 |
| ADK Roofing Limited | Construction | 2024 |
| Adlec Limited | Construction | 2003 |
| Adtechoptima Limited | Professional & scientific | 2024 |
| Advanced Care & Management Ltd | Health & social care | 2024 |
| Advanced Medic Solutions Ltd | Health & social care | 2025 |
| Advanced Nanotechnologies LAB Ltd | Other services | 2017 |
| Advanced Ruminant Holdings Limited | Financial services | 2018 |
| Advanced Ruminant Nutrition Limited | Wholesale & retail | 2006 |
| Advanced Staffing Solutions Ltd | Administrative & support | 2025 |
| Advanced Trailer Hire Limited | Transport & logistics | 2021 |
| Advanced Training Solutions Ltd | Education | 2025 |
| Advanced-Metering Ltd | Manufacturing | 2022 |
| Advantage Fabrication Limited | Manufacturing | 2003 |
| Aerial Vantage Ltd | Professional & scientific | 2021 |
| Afar Construction Limited | Construction | 2017 |
| Afar Group Ltd | Real estate | 2017 |
| Afar Holdings Ltd | Real estate | 2017 |
| Afar Properties Ltd | Real estate | 2017 |
| Afore YOU Ltd | Real estate | 2023 |
| Afripharma Limited | Professional & scientific | 2022 |
| AG Kirkland Developments Ltd | Agriculture & fishing | 2019 |
| AGE Agnostic Limited | Administrative & support | 2019 |
| AGE Together CIC | Education | 2026 |
| Aggro Ltd | Hospitality | 2024 |
| Agrico Services Limited | Transport & logistics | 2022 |
| Agsenze Ltd | Professional & scientific | 2016 |
| Agzg Limited | Real estate | 2024 |
| AHT TM Ltd | Construction | 2024 |
| Aiken Meadow Management Company Limited | Households | 2019 |
| Ainnovation Ltd | Information & communication | 2010 |
| AJ Engineering (NW) Ltd | Manufacturing | 2004 |
| Ajax Motors Limited | Wholesale & retail | 2022 |
| Ajgw Limited | Real estate | 2024 |
| AJM Dental Group Limited | Health & social care | 2021 |
| AJM Smile and Aesthetics Limited | Health & social care | 2020 |
| AJP Chefs Ltd | Administrative & support | 2022 |
| AJS Content Creation Ltd | Information & communication | 2023 |
| AJS Lancaster Limited | Financial services | 2023 |
| AK Kitchens Ltd | Construction | 2012 |
| Akengineeringmanagementservices Ltd | Professional & scientific | 2024 |
| Akila Logistics Ltd | Transport & logistics | 2023 |
| Albertech Limited | Information & communication | 2009 |
| Albion Mills Garage Limited | Wholesale & retail | 2014 |
| Aldcliffe Student Lets Limited | Real estate | 2019 |
| Aldcliffe Yard Management Company Limited | Real estate | 2014 |
| Alert Training Ltd | Professional & scientific | 2004 |
| Alessandra Reli Limited | Wholesale & retail | 2022 |
| Alex Palmer Plumbing & Heating Limited | Construction | 2013 |
| Alexandra Road Management Company (Morecambe) Limited | Real estate | 2023 |
| Alexika Limited | Professional & scientific | 1999 |
| ALL OUT Archers Limited | Manufacturing | 2021 |
| ALL Seasons Cleaning Solutions Ltd | Administrative & support | 2023 |
| Allan Associates Chtd. Surveyors Limited | Professional & scientific | 2002 |
| Allan Estates Limited | Real estate | 2021 |
| Allan Nicholson Limited | Extraterritorial | 2004 |
| Alltite Metal Roofing Systems Ltd | Construction | 1998 |
| Alluguard Limited | Manufacturing | 2010 |
| Alluvium Energy Ltd | Information & communication | 2026 |
| Alpha Nobel Limited | Professional & scientific | 2023 |
| Alpha Omega Legal Limited | Professional & scientific | 2011 |
| Alpine One Roofing Limited | Construction | 2019 |
| ALS Equine Ltd | Agriculture & fishing | 2026 |
| Also Antique Furniture Ltd | Wholesale & retail | 2023 |
| Alston + Donnelly Architecture Limited | Professional & scientific | 2013 |
| Altico Studio Ltd | Professional & scientific | 2013 |
| Alto A1 Limited | Transport & logistics | 2020 |
| Alto Leeds Limited | Transport & logistics | 2020 |
| Alvestowe Ltd | Real estate | 1958 |
| Alzol Limited | Financial services | 2025 |
| AM & Associates Ltd. | Professional & scientific | 2011 |
| Amanah Partnership Ltd | Real estate | 2007 |
| Amareen Lancaster Limited | Real estate | 2015 |
| Ambane Ltd | Real estate | 2025 |
| Amber Buddha Ltd | Information & communication | 2005 |
| Ambler Blackburn Financial Planning Ltd | Financial services | 2014 |
| Ambler Blackburn Limited | Financial services | 2010 |
| Ambry Bakery Ltd | Manufacturing | 2024 |
| AMD Energy Limited | Mining & quarrying | 2024 |
| American Sweet & Snacks (Lancaster) Ltd | Wholesale & retail | 2026 |
| Amma Therapy Limited | Other services | 2008 |
| Amro and Sons Properties Limited | Real estate | 2023 |
| AMU Spices Limited | Wholesale & retail | 2024 |
| Amzainsolutions Limited | Transport & logistics | 2018 |
| Anchor Flooring Limited | Construction | 2000 |
| AND the Gang Ltd | Health & social care | 2024 |
| AND7 Limited | Professional & scientific | 2018 |
| Anderton Fold Caravan Park Ltd. | Hospitality | 2011 |
| Andi Lewis Consultancy Ltd | Professional & scientific | 2022 |
| Andrew Ayrton Limited | Construction | 2003 |
| Andrew Loudon Traditional and Decorative Stonework Limited | Construction | 2005 |
| Andy Frobisher SEO Ltd | Information & communication | 2024 |