| Absolute Physiotherapy Limited | Health & social care | 2025 |
| AC Civils & Groundworks Ltd | Construction | 2025 |
| Academy 1 Sports Management Ltd | Administrative & support | 2018 |
| Acantha Crystals Limited | Wholesale & retail | 2022 |
| Acceron Industries Ltd | Construction | 2019 |
| Accession Property Investments Limited | Professional & scientific | 2017 |
| Ackerley Limited | Extraterritorial | 2020 |
| Acntbl Ltd | Information & communication | 2024 |
| Acorn Curtains and Blinds Ltd | Manufacturing | 2018 |
| ACS Cleaning Services Limited | Administrative & support | 2002 |
| Actif Software Limited | Administrative & support | 2022 |
| Action Reaction Training Ltd | Arts & recreation | 2015 |
| Active ARK Care Limited | Education | 2026 |
| Active ARK Limited | Education | 2001 |
| Active ARK Outdoors Limited | Extraterritorial | 2002 |
| Active Rural Equestrian CIC | Education | 2023 |
| Actual Limited | Administrative & support | 2025 |
| ACW Electrical Solutions Ltd | Administrative & support | 2017 |
| AD Outcomes Limited | Construction | 2015 |
| AD Waste Transfer Limited | Water & waste | 2008 |
| Adam Doyle Illustration Ltd | Professional & scientific | 2025 |
| Adam G Smith Limited | Construction | 2026 |
| Adam Kebab Ltd | Hospitality | 2025 |
| Adam's Safety Solutions Limited | Professional & scientific | 2020 |
| Adapt Beauty & Aesthetics Ltd | Other services | 2021 |
| ADC (Cumbria) Limited | Information & communication | 2007 |
| Additions Mobile Accessories Limited | Manufacturing | 2004 |
| ADE Logistics Ltd | Other services | 2025 |
| Adelphi Riverside AW LLP | | 2010 |
| Ademti Software Ltd | Information & communication | 2015 |
| Adgar Properties Ltd | Real estate | 2026 |
| Aditus Architectural Services Limited | Professional & scientific | 2016 |
| Aditus Property Services Ltd | Real estate | 2026 |
| ADL Bespoke Ltd | Manufacturing | 2023 |
| ADP Painting Limited | Other services | 2017 |
| ADR Health & Beauty Ltd | Other services | 2020 |
| Adrenaline International Limited | Arts & recreation | 2015 |
| Adriano's Carlisle Ltd | Hospitality | 2024 |
| ADS Electrical (Cumbria) Limited | Construction | 2023 |
| ADS Electrical Installation Ltd | Construction | 2014 |
| Advance Medispa Limited | Other services | 2014 |
| Advance Power Studies Limited | Construction | 2016 |
| Advanced Roofing & Property Maintenance Ltd | Construction | 2023 |
| Advanced Scaffolding (Carlisle) Limited | Construction | 2010 |
| Advantage Construction Services Ltd | Construction | 2022 |
| Advantage Flights Limited | Administrative & support | 1987 |
| Advantage Meetings and Events Limited | Professional & scientific | 2005 |
| Advantage Network Limited | Administrative & support | 2005 |
| Advantage Travel Transport Ltd | Administrative & support | 2019 |
| Adventure Collective Ltd | Professional & scientific | 2017 |
| Advissor Limited | Other services | 2018 |
| ADX Enviro Limited | Professional & scientific | 2021 |
| AE Futures Ltd | Real estate | 2026 |
| Aesthetics & Beauty Solutions Ltd | Wholesale & retail | 2019 |
| Aesthetics Skool Ltd | Health & social care | 2025 |
| AET Planning Limited | Professional & scientific | 2024 |
| AF Trustee Limited | Professional & scientific | 1994 |
| AFC Autism Ltd | Education | 2024 |
| AFG 1 Limited | Administrative & support | 2018 |
| Afgritech Limited | Manufacturing | 2004 |
| Afrikana CIC | Wholesale & retail | 2024 |
| After Shot Media Ltd | Professional & scientific | 2023 |
| AG Access Limited | Professional & scientific | 2023 |
| AGA Farm | Administrative & support | 2009 |
| AGE UK North Cumbria | Wholesale & retail | 2009 |
| Agenzia Limited | Wholesale & retail | 2013 |
| AGR (Cumbria) Ltd | Professional & scientific | 2018 |
| Agri-Accessories Limited | Other services | 2012 |
| Agrifeed Solutions Ltd | Wholesale & retail | 2021 |
| Agrigroup Limited | Administrative & support | 1995 |
| Agripharm Holdings Limited | Real estate | 2023 |
| AGT Plumbing & Heating Limited | Construction | 2011 |
| AHE Property Maintenance Ltd | Construction | 2022 |
| AHR 151 Limited | Financial services | 1984 |
| Aidan & Marmar Properties Limited | Real estate | 2023 |
| Aidan & Marmar Software Development Ltd | Information & communication | 2022 |
| Aidan Kirkley Plumbing & Heating Limited | Construction | 2023 |
| Ailearninguk Ltd | Manufacturing | 2026 |
| Aiola Contracts Ltd | Construction | 2023 |
| Air Sourced Ltd | Construction | 2022 |
| Aitken's Joinery Limited | Construction | 2015 |
| AJ African Market Ltd | Wholesale & retail | 2025 |
| AJ Sandelands Limited | Construction | 2019 |
| AJ Technical Training Limited | Professional & scientific | 2017 |
| AJC Roofing and Joinery Ltd | Construction | 2025 |
| AJI Engineering Ltd | Professional & scientific | 2013 |
| AJJ Electrical (North) Limited | Construction | 2024 |
| AJP Forklifts Ltd | Administrative & support | 2014 |
| AJP Sportsman Limited | Hospitality | 2020 |
| AJR Cumbria Limited | Extraterritorial | 2023 |
| AJR Motor Trading Ltd | Wholesale & retail | 2023 |
| Ajrandp Ltd | Professional & scientific | 2013 |
| AJW Asbestos Consultancy Services Ltd | Professional & scientific | 2018 |
| Akar CUT Ltd | Other services | 2025 |
| AKF Sports Coaching Limited | Extraterritorial | 2022 |
| Akivita Limited | Professional & scientific | 2024 |
| AKN Building & Joinery Ltd | Construction | 2005 |
| AKS Building & Joinery Limited | Construction | 2023 |
| Alan Blaylock Haulage Limited | Transport & logistics | 2013 |
| Alan Falder Haulage Ltd | Transport & logistics | 2008 |