| Buxton Road Management (Weymouth) Ltd | Households | 2012 |
| Buxton Stores Ltd | Wholesale & retail | 2014 |
| Buzzard Planning Services Limited | Construction | 2014 |
| BY E.G. Ltd | Professional & scientific | 2019 |
| BY the Quay Weymouth Ltd | Hospitality | 2024 |
| Bytefinity Ltd | Information & communication | 2023 |
| C & I Electrical Services Limited | Construction | 2016 |
| C & L Aviation Limited | Public administration | 2010 |
| C & R Davies Limited | Real estate | 1956 |
| C & S Locksmiths Limited | Construction | 2002 |
| C a Aerials Limited | Construction | 2010 |
| C D Read Building Services Limited | Construction | 2006 |
| C D Read Property Limited | Real estate | 2020 |
| C K Scaffolding Limited | Construction | 2015 |
| C ME Care Ltd | Health & social care | 2018 |
| C. Down Haulage Ltd | Transport & logistics | 2017 |
| Cackleberry Storage Limited | Transport & logistics | 2009 |
| Cadit Draughting Ltd | Professional & scientific | 2012 |
| Cadtek Design Limited | Professional & scientific | 2020 |
| Caerleon Court Management Limited | Households | 2004 |
| Cafe Blue (Weymouth) Ltd | Hospitality | 2025 |
| Cafe Monet Ltd | Hospitality | 2012 |
| Cafe Napoli Ltd | Hospitality | 2023 |
| Cafe on the Beach Ltd. | Hospitality | 2016 |
| Cafe Rico Limited | Wholesale & retail | 2015 |
| Caffeine 44 Limited | Hospitality | 2026 |
| Caffeine Weymouth Ltd | Hospitality | 2021 |
| Calebrations Party Services Ltd | Administrative & support | 2023 |
| Callvalley Limited | Health & social care | 2006 |
| Cambridge Court (Verne Road) Management Company Limited | Households | 2000 |
| Cambridge Software Development Ltd | Information & communication | 2008 |
| Cammas IG Limited | Real estate | 2021 |
| Cane Traders Limited | Wholesale & retail | 2024 |
| CAP D'Agde Select Limited | Hospitality | 1999 |
| Carbon Coast Limited | Other services | 2019 |
| Carbon Strategic Management Group Limited | Energy | 2022 |
| Carlo Oliveri Ltd | Financial services | 2025 |
| Carlton Court, 22 Carlton Road South (Weymouth) Limited | Hospitality | 1986 |
| Carltonwey Holdings Ltd | Real estate | 2022 |
| Carltonwey Ltd | Real estate | 2023 |
| Carolan Construct Ltd | Construction | 2026 |
| Carp Circle Limited | Administrative & support | 2020 |
| Carpet Price Limited | Wholesale & retail | 2018 |
| Carriageworks Commercial Ltd | Real estate | 2024 |
| Carrington Financial Consultancy Ltd | Financial services | 2014 |
| Cars First Ltd | Wholesale & retail | 2024 |
| Cartails and Events Limited | Hospitality | 2021 |
| Carter Sxciety Clothing Ltd | Wholesale & retail | 2024 |
| Casa DEL Duende Ltd | Manufacturing | 2013 |
| Casa WEY Ltd | Construction | 2024 |
| Casanova Investments Limited | Households | 2011 |
| Cash Generator Merseyside Limited | Wholesale & retail | 2026 |
| Cashboyz Ltd | Wholesale & retail | 2025 |
| Caslas Labs Limited | Information & communication | 2018 |
| Casterbridge Care & Mobility Ltd | Administrative & support | 2009 |
| Casterbridge Hardy (Dorchester) Limited | Professional & scientific | 1980 |
| Casterbridge Hardy (Gibraltar) LLP | | 2021 |
| Casterbridge Hardy LLP | | 2006 |
| Casterbridge Ltd | Hospitality | 2008 |
| Castle Music Limited | Wholesale & retail | 2015 |
| Castleman Properties Limited | Real estate | 2015 |
| Castletown Beach Tenants Ltd | Households | 2021 |
| Catch@The Old Fish Market Limited | Hospitality | 2020 |
| Catercare Warewash Systems Ltd | Manufacturing | 2018 |
| Cats Diary Ltd | Agriculture & fishing | 2025 |
| Caviar Plaice Weymouth Limited | Hospitality | 2023 |
| Cbta Community Interest Company | Hospitality | 2022 |
| CC Aviation Ltd | Manufacturing | 2024 |
| Ccclx Music Ltd | Information & communication | 2013 |
| CCW Enterprise Ltd | Real estate | 2010 |
| CD Walsh Consultancy and Training Ltd | Administrative & support | 2009 |
| CDI Holdings Limited | Real estate | 2017 |
| CDI Services (Portland) Ltd | Manufacturing | 2001 |
| Cdm-C Consultants Ltd | Administrative & support | 2013 |
| Cdmaz Limited | Wholesale & retail | 2023 |
| Celtic Holidays (SW) Limited | Hospitality | 2024 |
| Central London Counselling Services Limited | Health & social care | 2006 |
| Ceti Alpha 5 Ltd. | Education | 2024 |
| Cetrek Ltd | Professional & scientific | 2006 |
| Chalbury Building Design Limited | Professional & scientific | 2007 |
| Chalbury Wine Stores Limited | Wholesale & retail | 2004 |
| Chalklands Management Co Ltd | Households | 2020 |
| Challenge Leisure Limited | Arts & recreation | 2005 |
| Challenger GAS Ltd | Professional & scientific | 2020 |
| Chambers & SON Roofing Ltd | Construction | 2020 |
| Chambers Property Care Limited | Construction | 2002 |
| Chandlers Apartments Management Ltd. | Households | 2015 |
| Chapelhay Tavern Ltd | Hospitality | 2023 |
| Chapter One Hotels Limited | Wholesale & retail | 2021 |
| Charles Safety Ltd | Public administration | 2025 |
| Charlotte Guesthouse (Weymouth) Limited | Hospitality | 2015 |
| Charm Properties Limited | Real estate | 2002 |
| Charmed Glow Aesthetics Limited | Other services | 2025 |
| Charminster Stores Limited | Wholesale & retail | 2013 |
| Charter Royle Ltd | Professional & scientific | 2007 |
| Checkdam Ltd | Professional & scientific | 2025 |
| Chef Honour Limited | Hospitality | 2018 |
| Chesil Beach Cafe Ltd | Hospitality | 2024 |
| Chesil Beach Developments Limited | Financial services | 2016 |
| Chesil Beach Holdings Limited | Financial services | 2021 |