| 0911MINING Ltd | Wholesale & retail | 2020 |
| 29029 Wareham Ltd | Hospitality | 2026 |
| 2HG Legal Consultancy Ltd | Professional & scientific | 2022 |
| 8E Design Ltd | Professional & scientific | 2020 |
| A Blume Ltd | Other services | 2003 |
| A.W. Precision Engineering Limited | Manufacturing | 1997 |
| Able Care Dorset Ltd | Health & social care | 2024 |
| Accent Press Limited | Information & communication | 2003 |
| Activ Power and Sail Limited | Transport & logistics | 2003 |
| Adventures for Wellbeing Ltd | Health & social care | 2024 |
| AG Design (Dorset) Ltd | Professional & scientific | 2016 |
| Aggie Holdings Limited | Financial services | 2024 |
| AGS Plasterers Ltd | Construction | 2021 |
| Airborne Representation Limited | Administrative & support | 2006 |
| Ajdj Woods Ltd | Hospitality | 2025 |
| Alan Smith Landscaping Limited | Administrative & support | 2003 |
| Alaska Ecological Contracting Ltd | Construction | 1997 |
| Alaska Limited | Administrative & support | 1998 |
| Alchem-Ai Ltd | Information & communication | 2023 |
| Alder Structural Engineering Ltd | Professional & scientific | 2024 |
| ALL Products Direct Ltd | Wholesale & retail | 2006 |
| Alpine Property Surveys Ltd | Professional & scientific | 2019 |
| Always Welcome Enterprises Ltd | Hospitality | 2012 |
| AMA Lurra Limited | Wholesale & retail | 2026 |
| AMG Driven Limited | Transport & logistics | 2025 |
| Anatrack Limited | Administrative & support | 2000 |
| AND Fragrance Ltd | Manufacturing | 2020 |
| Anderfield Investments Limited | Real estate | 1984 |
| Andy Cole Financial Planning Ltd | Professional & scientific | 2020 |
| Anglebury Asset Management Limited | Financial services | 2008 |
| Anglebury Financial Associates LLP | | 2013 |
| Anglebury Financial Services Limited | Professional & scientific | 2026 |
| ANM Pharma Ltd | Professional & scientific | 2025 |
| AP Swanage Taxis Ltd | Transport & logistics | 2024 |
| Aqua GAS Dorset Plumbing and Heating Ltd | Construction | 2024 |
| Arabica Knights Limited | Wholesale & retail | 2015 |
| ARC Recruits Ltd | Administrative & support | 2022 |
| ARD Construction and Home Maintenance Ltd | Construction | 2017 |
| Arish Barber Shop Ltd | Other services | 2022 |
| Ariyella Ltd | Wholesale & retail | 2024 |
| Arne Retail Ltd | Extraterritorial | 2024 |
| Arne Water Company Limited | Water & waste | 1987 |
| Arnold-Jones Ltd | Construction | 2001 |
| Arny Properties Ltd | Real estate | 2020 |
| Arthur M.C. Ltd | Information & communication | 2025 |
| Assaye Defence Consultancy Ltd | Professional & scientific | 2018 |
| Astrocal Limited | Wholesale & retail | 2019 |
| Athena Theatre Works & Productions Ltd | Education | 2019 |
| Atomic Health Communications Ltd | Professional & scientific | 2020 |
| Aurora Group Holdings Ltd | Financial services | 2025 |
| Austrian Alpine Club (UK) Limited | Other services | 2015 |
| AXE the WAX Ltd | Health & social care | 2025 |
| B & R Auto 8PS Limited | Administrative & support | 2025 |
| B Andrews Properties Limited | Real estate | 2024 |
| B Andrews Property Maintenance Ltd | Construction | 2022 |
| B Curtis Farm Shop Ltd | Real estate | 2025 |
| B G Homes Limited | Real estate | 2001 |
| B W Construction & Groundworks Ltd | Construction | 2020 |
| B&M Landscapes Ltd | Administrative & support | 2014 |
| B.C Flooring Ltd | Construction | 2025 |
| Bankes Arms (Corfe Castle) Ltd | Hospitality | 2025 |
| Bare Necessities (Dorset) Ltd | Wholesale & retail | 2019 |
| Barons Court (Poole) Management Company Limited | Administrative & support | 1994 |
| Barree Collective Ltd | Real estate | 2017 |
| Barrow Wood LLP | | 2020 |
| Beak and Claw Limited | Real estate | 2019 |
| Bear Bites Limited | Hospitality | 2018 |
| Bear Naps at Wareham Ltd | Hospitality | 2020 |
| BH20 Private Hire Ltd | Administrative & support | 2021 |
| Big Dreams Limited | Wholesale & retail | 2002 |
| Bingham & Wates Limited | Real estate | 2003 |
| Biotrack Ltd | Manufacturing | 2017 |
| Birchwood Storage Limited | Transport & logistics | 2014 |
| Bland (the Beehive) Limited | Real estate | 2008 |
| Bland Group UK Holdings Limited | Professional & scientific | 2007 |
| Bland Orbit Limited | Transport & logistics | 2021 |
| Bland Technologies Limited | Information & communication | 2020 |
| Blast Sport Ltd | Arts & recreation | 2005 |
| Bloom Golf Ltd | Wholesale & retail | 2026 |
| Bloomfield Care Ltd | Health & social care | 2019 |
| Blossom Beauty Clinic Ltd | Health & social care | 2021 |
| Bloxworth Capital Partners Limited | Extraterritorial | 1999 |
| Bloxworth Estate Limited | Real estate | 1964 |
| Blue Cloud Music Ltd | Information & communication | 2024 |
| Blue Dixie Ltd | Hospitality | 2024 |
| Blue Puffin Medical Limited | Health & social care | 2025 |
| Bokella Limited | Financial services | 2020 |
| Bonita Martina Childrenswear Ltd | Wholesale & retail | 2019 |
| Bournemouth & Poole Tourism Board Ltd | Administrative & support | 2025 |
| Bovington Management (NO 2) Company Limited | Households | 1996 |
| Brace of Butchers LLP | | 2014 |
| Brewow Ltd | Manufacturing | 2024 |
| Browning Forestry Ltd | Agriculture & fishing | 2012 |
| BTO (Shitterton) Management Company Limited | Households | 2017 |
| Butterfly Conservation | Administrative & support | 1987 |
| BW Property Southern Ltd | Professional & scientific | 2025 |
| BY (Dorset) Properties Ltd | Administrative & support | 2017 |
| C and B Enterprise Ltd | Hospitality | 2018 |
| C.E. Barnes & Sons (Wareham) Limited | Agriculture & fishing | 1972 |
| Caiger Language Services Ltd. | Professional & scientific | 2014 |