| Applegate Park Open Space Management Company Limited | Households | 2021 |
| Apsleys LLP | | 2020 |
| Arbland Ltd | Agriculture & fishing | 2021 |
| Archerton Group Limited | Professional & scientific | 2018 |
| Archibald Nott and Sons Limited | Mining & quarrying | 1972 |
| ARI Panzer Animation Ltd | Arts & recreation | 2023 |
| Arscott & Western Ltd | Construction | 2003 |
| Artemis Natural Capital Ltd | Professional & scientific | 2025 |
| Artificial Intelligence Made Simple Ltd | Professional & scientific | 2025 |
| Arvente Ltd | Professional & scientific | 2025 |
| Asc-Key Limited | Information & communication | 2025 |
| Asgardian IT & Cloud Solutions Limited | Information & communication | 2022 |
| ASH Garden Designs & Landscaping Limited | Other services | 2002 |
| ASH Group (SW) Ltd | Construction | 2017 |
| Ashcross Management Company Limited | Households | 2003 |
| Ashilford Properties Limited | Real estate | 2009 |
| Ashley Court Devon Ltd | Hospitality | 2021 |
| Aspara Limited | Financial services | 2016 |
| Aspyre Solutions Ltd | Administrative & support | 2017 |
| Associated Business Centre Limited | | 1985 |
| AT NO.7 Ltd | Other services | 2024 |
| ATF Electrical and Renewable Limited | Construction | 2025 |
| Audio Destination Ltd | Wholesale & retail | 2002 |
| Autologik Limited | Wholesale & retail | 2009 |
| AV Tech Productions Ltd | Information & communication | 2026 |
| Avago Club Limited | Information & communication | 2023 |
| Avalon Scaffolding Ltd | Construction | 2016 |
| Avenel Ltd | Real estate | 2019 |
| Avocet Renewables Limited | Energy | 2014 |
| Awkward Pigeon Theatre LLP | | 2024 |
| Axminster Management Limited | Households | 1990 |
| B & M Techniques Limited | Health & social care | 2003 |
| B C Automotive Services Ltd | Wholesale & retail | 2015 |
| B Edworthy Contracting Ltd | Agriculture & fishing | 2021 |
| B Kent IT Ltd | Information & communication | 2025 |
| B R Carter Ltd | Construction | 2018 |
| B.E. Loveday Precision Engineering Limited | Manufacturing | 1978 |
| B3 Therapy Ltd | Health & social care | 2020 |
| Baby Bull Properties Ltd | Real estate | 2026 |
| Baby Squids Devon Ltd | Arts & recreation | 2021 |
| Babywearing UK CIC | Education | 2010 |
| Bailey Wood Ltd | Manufacturing | 2011 |
| Bailper Ltd | Information & communication | 2020 |
| Baitshed Ltd | Wholesale & retail | 2026 |
| Baker Murray Bookkeeping Ltd | Professional & scientific | 2020 |
| Bali Property Development Management Ltd | Real estate | 2025 |
| Ballykenny Solar Limited | Energy | 2018 |
| Barle Valley Forestry Ltd | Agriculture & fishing | 2015 |
| Barnhaze Accountancy Ltd | Professional & scientific | 2023 |
| Barok Ltd | Hospitality | 2026 |
| Barry Sleight Ltd | Professional & scientific | 2019 |
| Bartin Plumbing and Heating Limited | Construction | 2009 |
| Bateman Hosegood Ltd | Professional & scientific | 2014 |
| Bathroom 2000 Limited | | 1982 |
| Bbsm Ltd | Manufacturing | 2019 |
| Beaty Properties Ltd | Real estate | 2025 |
| Beaver Estates (Ashford) Investments Limited | Real estate | 1968 |
| Becketts of Sidmouth LLP | | 2018 |
| BEE Meadow (South Molton) Management Company Ltd | Households | 2018 |
| Beechcliff Limited | Agriculture & fishing | 1989 |
| Bellams Properties Ltd | Real estate | 2009 |
| Belstone View Management Company Limited | Households | 2024 |
| Besley 1964 Limited | Extraterritorial | 2013 |
| Bespoke CRM Consultancy Ltd | Information & communication | 2026 |
| Bespoke Installations SW Limited | Construction | 2008 |
| Bewilder Consulting Ltd | Professional & scientific | 2026 |
| Bexham Consultants Limited | Information & communication | 2003 |
| Big BLU Limited | Manufacturing | 2001 |
| Bill Longland's Engineering Services Limited | Professional & scientific | 2015 |
| Bimble Ltd | Construction | 2022 |
| Bingwell House Management Company Limited | Households | 1976 |
| Bitespire Ltd | Information & communication | 2018 |
| Blackerton Ecocentre CIC | Education | 2014 |
| Blackmore Vale Vets Ltd | Professional & scientific | 2024 |
| Blakes Coaches Limited | Administrative & support | 2002 |
| Blissview Ltd | Real estate | 2023 |
| Blo-Tech Limited | Manufacturing | 1998 |
| Blubox Developments Limited | Construction | 2019 |
| Blubox Living Limited | Real estate | 2026 |
| Bludoor Property Management Ltd | Real estate | 2026 |
| Bluebell and Lark Limited | Wholesale & retail | 2023 |
| Blundell's School | Education | 2000 |
| Blyth Construction (SW) Ltd | Construction | 2013 |
| Both Sides NOW Developments Limited | Construction | 2018 |
| Botley Management Company Limited | Real estate | 1992 |
| Bowbier Ltd | Financial services | 2025 |
| Bowden Hill Holdings Limited | Real estate | 2026 |
| Bradleigh Down Ltd | Hospitality | 2024 |
| BRAILLE4RAIL Ltd | Professional & scientific | 2022 |
| Bramley Homes (South West) Limited | Real estate | 2005 |
| Bray Accountants Limited | Professional & scientific | 2002 |
| Breakaway Effects Ltd. | Manufacturing | 1997 |
| Bridge Troll at the Old Library Ltd | Wholesale & retail | 2026 |
| Bridwell Game Limited | Agriculture & fishing | 2019 |
| Brightling UK Limited | Real estate | 2000 |
| Brightowl Limited | Professional & scientific | 2014 |
| Brilliant Errror C.I.C. | Administrative & support | 2025 |
| Brinkley Grays Ltd | Arts & recreation | 2025 |
| Bristol Dog Field Limited | Arts & recreation | 2024 |
| Brithayes Properties Ltd | Real estate | 2025 |