| Apex Mechanical Engineers Limited | Real estate | 2012 |
| Apex Property Group and Maintenance Ltd | Households | 2026 |
| API Mechanical Services Limited | Construction | 2008 |
| Apogee (North) Limited | Construction | 2015 |
| Apollo Air Services Limited | Transport & logistics | 2013 |
| Apollo Storage Ltd | Transport & logistics | 2021 |
| Approved Roofing Carlisle Limited | Construction | 2020 |
| Approved Roofing Cumbria Limited | Construction | 2024 |
| Aquatecnic Estate Holdings Limited | Financial services | 2026 |
| Aquatecnic Estates Limited | Other services | 2026 |
| AR Building Services Limited | Construction | 2005 |
| AR Carlisle Limited | Construction | 2025 |
| AR Technical Engineering Ltd | Professional & scientific | 2022 |
| ARB Access Services Ltd | Arts & recreation | 2018 |
| ARB Management Ltd | Professional & scientific | 2012 |
| ARB Specialist Access Ltd | Construction | 2026 |
| ARC Business Improvements Limited | Professional & scientific | 2013 |
| ARC Property Solutions Ltd | Real estate | 2025 |
| Arcade Bar Limited | Hospitality | 2021 |
| Arch 7 Enterprises Limited | Hospitality | 2025 |
| Arch Bar Ltd | Hospitality | 2025 |
| Arches Project Management Ltd | Professional & scientific | 2025 |
| Architects Plus (UK) Limited | Professional & scientific | 2001 |
| Archive Research Centre Ltd | Information & communication | 2026 |
| Archveer Limited | Construction | 1985 |
| Argyll Drive Management Company 1 Limited | Real estate | 2004 |
| Argyll Drive Management Company 2 Limited | Administrative & support | 2004 |
| ARK Konditioning Ltd | Arts & recreation | 2026 |
| ARM Experiential Limited | Professional & scientific | 2013 |
| Armbley Transport Limited | Administrative & support | 2022 |
| Armeria (UK) LLP | | 2008 |
| Arms Hotel (Shap) Limited | Hospitality | 2017 |
| Armstrong & Denton LLP | | 2011 |
| Armstrong & Liddle Plumbing & Heating Limited | Construction | 2005 |
| Armstrong and Denholm Ltd | Wholesale & retail | 2020 |
| Armstrong Auto Trading Ltd | Wholesale & retail | 2023 |
| Armstrong Building Supplies Limited | Wholesale & retail | 2000 |
| Armstrong Eco Systems Limited | Construction | 2020 |
| Armstrong Engineering Services Limited | Professional & scientific | 2021 |
| Armstrong Henderson Limited | Real estate | 2015 |
| Armstrong House Management Company Limited | Real estate | 2015 |
| Armstrong Plant Limited | Construction | 2023 |
| Armstrong Reiver BBS Ltd | Real estate | 2000 |
| Armstrong Reiver LLP | | 2012 |
| Armstrong Watson Audit Holdings Limited | Professional & scientific | 2011 |
| Armstrong Watson Audit Limited | Professional & scientific | 2013 |
| Armstrong Watson Financial Planning Ltd | Financial services | 2010 |
| Armstrong Watson LLP | | 2017 |
| Armstrong Watson Residential Property Fund | | 2006 |
| Armstrong Watson Trustees Limited | Professional & scientific | 2013 |
| Aroma Deli Limited | Hospitality | 2025 |
| Arrival Downhole Tools UK Ltd. | Manufacturing | 2011 |
| Arrocarlisle Ltd | Hospitality | 2023 |
| Arrow Education Limited | Education | 2002 |
| Arrow Quantity Surveyors Limited | Professional & scientific | 2014 |
| Arrow Web Solutions Ltd. | Information & communication | 2011 |
| Art & Oak Ltd | Construction | 2019 |
| Art Services (Cumbria) Limited | Transport & logistics | 2017 |
| Arti & HU Limited | Real estate | 2012 |
| Artyrose Ltd | Hospitality | 2025 |
| Arya Culinary Ltd | Hospitality | 2025 |
| Aryan Market Ltd | Wholesale & retail | 2026 |
| Asbd 1 Limited | Construction | 2025 |
| Asbridge Builders Limited | Construction | 2005 |
| Ascend T Ltd | Administrative & support | 2024 |
| Ascent Management Ltd | Professional & scientific | 2015 |
| ASH LEA Cargo Ltd | Real estate | 2024 |
| ASH Tree Park Management Company Limited | Households | 2016 |
| Ashby London (PP) Trustees Limited | Extraterritorial | 1996 |
| Ashby London Trustees Limited | Extraterritorial | 1996 |
| Ashleigh's Domestic Services Ltd | Administrative & support | 2025 |
| Ashtree Property Management Ltd | Administrative & support | 2017 |
| Ashwood Design Associates Limited | Professional & scientific | 2008 |
| Asiduo Ltd | Real estate | 2026 |
| ASK Health & Wellbeing Solutions Ltd | Professional & scientific | 2016 |
| Asked Consultancy Limited | Health & social care | 2022 |
| Askhelen Limited | Professional & scientific | 2023 |
| Askj Consultancy Services Limited | Administrative & support | 2019 |
| ASL Carlisle Limited | Construction | 2025 |
| ASM Properties (Carlisle) Ltd | Real estate | 2025 |
| Asmtm Services Limited | Wholesale & retail | 2009 |
| Asnoki Limited | Health & social care | 2025 |
| Aspect Windows and Doors Ltd | Construction | 2020 |
| Aspen Grange (Carlisle) Management Company Limited | Real estate | 2018 |
| Asphales Safety & Environmental Management Ltd | Professional & scientific | 2020 |
| Aspire Assistive CIC | Information & communication | 2017 |
| Aspire Care Cumbria Developments Limited | Financial services | 2026 |
| Aspire Care Cumbria Limited | Health & social care | 2019 |
| Aspire Consulting Europe Limited | Professional & scientific | 2007 |
| Asquith House Management Company Limited | Real estate | 2011 |
| Assured Rest Hotels Ltd | Hospitality | 2006 |
| Astbury Meadow Garden Centre Limited | Extraterritorial | 1972 |
| Aston Logistics Ltd | Transport & logistics | 2022 |
| Asya Carlisle Ltd | Hospitality | 2023 |
| AT Capital Ltd | Administrative & support | 2016 |
| AT Cause Ltd | Professional & scientific | 2020 |
| ATC Props Ltd | Information & communication | 2016 |
| Athena Pallas Limited | Wholesale & retail | 2024 |
| Atherton Corporate Partners LLP | | 2017 |
| Atkinson Automotive Ltd | Wholesale & retail | 2023 |