| BON Accord Residents Company Limited | Households | 1974 |
| Bournemouth Cars Ltd | Wholesale & retail | 2013 |
| Boyne Court (Swanage) Limited | Households | 2007 |
| Breps LLP | | 2007 |
| Brian Glassock Builders Limited | Construction | 2002 |
| Bricks & Stones Ltd | Construction | 2013 |
| Bridport Cycles Limited | Wholesale & retail | 2015 |
| Britannia Hospitality Solutions Ltd | Hospitality | 2012 |
| Broad Leys Management Company Limited | Households | 2006 |
| Broad Reach Investments LLP | | 2020 |
| Brook Tea Rooms Ltd | Hospitality | 2023 |
| Bucknowle Services Ltd | Professional & scientific | 2002 |
| Burden Building Services Limited | Construction | 2002 |
| Burlington Court (Swanage) Management Limited | Households | 2001 |
| Burlington Retrofit C.I.C. | Administrative & support | 2022 |
| Burnt Toast Dorset Limited | Hospitality | 2024 |
| Burts Bits Ltd | Wholesale & retail | 2018 |
| Business Ambition Community CIC | Administrative & support | 2025 |
| Business Century Systems Limited | Information & communication | 1997 |
| Butler Plumbing & Heating Limited | Construction | 2005 |
| Buzzcut Productions Ltd | Arts & recreation | 2024 |
| BY Phaedra Limited | Wholesale & retail | 2024 |
| C & C Engineering Ltd | Construction | 2015 |
| C a Symes Painter and Decorator Limited | Construction | 2012 |
| C and K Dudley Limited | Hospitality | 2019 |
| CAG Partners LLP | | 2005 |
| CAGP2 LLP | | 2013 |
| Campbell Clarke Construction Ltd | Construction | 2018 |
| Camping Ltd | Hospitality | 2017 |
| Capstone Inspections Ltd | Administrative & support | 2008 |
| Carve Coffee Roasters Ltd | Manufacturing | 2020 |
| Casa DI Vini Ltd | Wholesale & retail | 2015 |
| Casa LMT Ltd | Real estate | 2018 |
| Casca Textiles Limited | Manufacturing | 2021 |
| Castle & Cottage Ltd | Real estate | 2017 |
| Castle Mount Flat Management Company Limited | Professional & scientific | 2003 |
| CCC Properties Limited | Real estate | 2024 |
| CDC Southern Limited | Real estate | 2023 |
| Centralside Property Management Limited | Households | 1987 |
| CFO Consulting Limited | Professional & scientific | 2019 |
| Chapman's Good Food Company Ltd | Hospitality | 2007 |
| Charlotte's Pet Care Services Ltd | Other services | 2024 |
| Chartis Fleet Management Ltd | Transport & logistics | 2023 |
| Chelsfield Advisers LLP | | 2005 |
| Chelsfield Asset Management Limited | Extraterritorial | 2014 |
| Chelsfield Corporate Services Limited | Extraterritorial | 2008 |
| Chelsfield Developments (Kensington) Limited | Construction | 2011 |
| Chelsfield France Limited | Real estate | 2014 |
| Chelsfield Group Limited | Financial services | 2014 |
| Chelsfield Holdings Limited | Professional & scientific | 2014 |
| Chelsfield Investment Management Limited | Extraterritorial | 2014 |
| Chelsfield KE LLP | | 2010 |
| Chelsfield LLP | | 2012 |
| Chelsfield Mews Services Limited | Real estate | 2007 |
| Chequers Management (Swanage) Limited | Households | 2006 |
| Chilled Red Limited | Hospitality | 2009 |
| Chiltern Wood Recycling Project | Water & waste | 2008 |
| China Association for Management of Technology Ltd | Administrative & support | 2006 |
| Chris Caldicott Limited | Professional & scientific | 2002 |
| Christchurch Performance Cars Limited | Wholesale & retail | 2014 |
| Church Close Residents Association Limited | Other services | 1976 |
| Churchwood Court (Wareham) Limited | Households | 1981 |
| Cinisco Ltd | Extraterritorial | 2015 |
| Citico Limited | Professional & scientific | 2011 |
| Classic and Military Models Ltd | Extraterritorial | 2015 |
| Classic Restoration (Furniture) Limited | Other services | 2004 |
| Classic Yacht Brokerage Limited | Wholesale & retail | 2026 |
| Claw Commercial Ltd | Extraterritorial | 2014 |
| Cleanbeee Services Ltd | Administrative & support | 2025 |
| Clifton Close (Swanage) Limited | Households | 1977 |
| Clifton Flats Limited | Households | 2016 |
| Cloud Arboretum Ltd | Information & communication | 2019 |
| Coastal Crockery Ltd | Administrative & support | 2025 |
| Coastal Crust Limited | Hospitality | 2023 |
| Coastal Tents Ltd | Administrative & support | 2015 |
| Coldtime Limited | Other services | 2012 |
| Collectors Cove TCG Ltd | Wholesale & retail | 2026 |
| Commercial Accounting & Taxation Ltd | Professional & scientific | 2016 |
| Commercial Loans & Finance Funding Ltd | Financial services | 2015 |
| Commercial Loans & Finance Ltd | Financial services | 2015 |
| Conceptual Homes Limited | Construction | 2012 |
| Control Components Limited | Real estate | 1948 |
| Corbeau House Limited | Households | 2018 |
| Cordial Knots Ltd | Wholesale & retail | 2022 |
| Corfe Castle Brewery Limited | Extraterritorial | 2006 |
| Corfe Castle Cider Company Ltd | Wholesale & retail | 2011 |
| Corfe Construction Ltd | Construction | 2012 |
| Coronel Estates Ltd | Real estate | 2005 |
| Country Foods (Swanage) Limited | Wholesale & retail | 2002 |
| Country Garden Plant Sales Limited | Agriculture & fishing | 2002 |
| County Wine Festivals Limited | Administrative & support | 2026 |
| Court Hill Wines Ltd | Wholesale & retail | 2012 |
| CPK Empowering Families Limited | Health & social care | 2012 |
| Crab Apple Catering Limited | Hospitality | 2015 |
| Crab Apple Holding Limited | Financial services | 2023 |
| Craig-Y-Don (Swanage) Limited | Households | 1995 |
| Cranborne (Swanage) Limited | Households | 2024 |
| Creative Audio Visual and Events Limited | Arts & recreation | 2004 |
| Creative Property 1 Limited | Real estate | 2024 |
| Creative Property Estate Management Limited | Real estate | 2025 |