| Bryn Golds Plumbing and Heating Limited | Construction | 2016 |
| BS & Conservation Ltd | Arts & recreation | 2004 |
| BSJ Housing Solutions C.I.C. | Construction | 2026 |
| BTS Pubs Ltd | Hospitality | 2022 |
| Buckley Prichard International Limited | Administrative & support | 2003 |
| Buckley Wand Ltd | Real estate | 2009 |
| Buckminster Broadband Limited | Information & communication | 2012 |
| Buckminster Developments Limited | Construction | 1965 |
| Buckminster Farming Company Limited | Professional & scientific | 1981 |
| Buckminster Gliding Club Limited | Arts & recreation | 1974 |
| Buckminster Management Limited | Other services | 1980 |
| Buddy Housing Ltd | Households | 2019 |
| Bujak Property Ltd | Real estate | 2022 |
| Bull Roomzzz Limited | Real estate | 2026 |
| Burghley Court Stamford Management Limited | Households | 1985 |
| Burghley Plasterers Eastern Limited | Construction | 2008 |
| Burkin Associates Limited | Professional & scientific | 2017 |
| Burton Aviation Limited | Transport & logistics | 2015 |
| Burtonstone Construction Ltd | Construction | 2025 |
| Business Administration & Accountancy Services Limited | Professional & scientific | 2015 |
| Business Management Solutions Limited | Real estate | 2025 |
| Butterfly Ball Car Hire Ltd | Administrative & support | 2025 |
| Buxstone Limited | Real estate | 2020 |
| Bwdcivils Limited | Construction | 2025 |
| BWS Industrial Services Limited | Construction | 2009 |
| BXI Ltd | Professional & scientific | 2019 |
| Bygott Sporting Limited | Education | 2022 |
| Bywater Finance Ltd | Financial services | 2026 |
| C & N Locums Limited | Health & social care | 2013 |
| C B Thompson Limited | Agriculture & fishing | 2022 |
| C Central Limited | Hospitality | 2025 |
| C F W Removals Ltd | Transport & logistics | 2004 |
| C S Pask Holdings Limited | Real estate | 2015 |
| C Y O (Agencies) Ltd | Wholesale & retail | 2017 |
| C-Tech Consulting Ltd | Professional & scientific | 2017 |
| C.C Auto's Breakdown & Recovery Ltd | Wholesale & retail | 2024 |
| C.C Building Services Ltd | Construction | 2025 |
| C.J. Farms Limited | Agriculture & fishing | 1996 |
| C.P.A. Services Limited | Wholesale & retail | 1988 |
| C.S.S. Engineering Limited | Manufacturing | 1993 |
| C7 Nameco Limited | Financial services | 2008 |
| C7 PVT Ltd | Professional & scientific | 2016 |
| Cake Central Ltd | Hospitality | 2024 |
| Calabria Holdings Limited | Financial services | 2024 |
| Caleu Autos Ltd | Wholesale & retail | 2023 |
| Calm Aviation Ltd | Information & communication | 2022 |
| Calvor Ltd | Wholesale & retail | 2025 |
| Camco (Stonegate) Limited | Administrative & support | 2000 |
| Cameron James Group Limited | Real estate | 2025 |
| Cameron’S Crafts Ltd | Wholesale & retail | 2025 |
| Canary Safety Ltd | Professional & scientific | 2022 |
| Capital Protections Ltd | Administrative & support | 2021 |
| Caravan Sales UK Limited | Wholesale & retail | 2018 |
| Cardinal Accountancy (Grantham) Limited | Professional & scientific | 2025 |
| Cardinal Accountancy Services Limited | Professional & scientific | 2002 |
| Cardinal Bookkeeping (Grantham) Limited | Professional & scientific | 2025 |
| Cardinal Bookkeeping Services Limited | Professional & scientific | 2008 |
| Care Candy Limited | Manufacturing | 2023 |
| Caring Companions 4U Ltd | Health & social care | 2017 |
| Carinthian Limited | Wholesale & retail | 2016 |
| Carla Hospitalities Limited | Hospitality | 2022 |
| Carlee Investments Limited | Real estate | 2024 |
| Carlisle Blinds Grantham Limited | Wholesale & retail | 2019 |
| Carlton Scroop Estates Ltd | Real estate | 2024 |
| Carmen Moldovan Ltd | Health & social care | 2017 |
| Carmilton Limited | Wholesale & retail | 2025 |
| Carolant Underwriting LLP | | 2007 |
| Carrs Consulting Ltd | Professional & scientific | 2022 |
| Carsay Underwriting LLP | | 2008 |
| Cartwright Engineering Services Limited | Construction | 2019 |
| Casa Revo Limited | Extraterritorial | 2019 |
| Casalana Ltd | Real estate | 2025 |
| Cast Components (UK) Limited | Manufacturing | 2011 |
| Casters Bait LP | | 2017 |
| Castlegate Independent Financial Advisers Limited | Professional & scientific | 1998 |
| Castlegate Wealth (Holdings) Limited | Financial services | 1998 |
| Castlegate Wealth Management Limited | Professional & scientific | 1997 |
| Castra Nova Training Limited | Professional & scientific | 2019 |
| Catalin Popescu Catalin Solution Ltd | Transport & logistics | 2026 |
| Catherine Gilchrist Catering Limited | Hospitality | 2015 |
| Cathodic Protection Co. Limited | Manufacturing | 1950 |
| Caythorpe Farmers LLP | | 2008 |
| Caythorpe GAS & OIL Services Limited | Construction | 2008 |
| Caythorpe Holdings Limited | Financial services | 2022 |
| Caythorpe Stores Ltd | Wholesale & retail | 2022 |
| CB Taxis Ltd | Transport & logistics | 2021 |
| CBC Solutions Ltd | Administrative & support | 2024 |
| Cbgt - Hypnotherapy & Counselling Service Ltd | Health & social care | 2023 |
| CC Health Ltd | Health & social care | 2025 |
| CD2M Services Ltd | Administrative & support | 2013 |
| CDL Specialist Contractors Ltd | Construction | 2026 |
| CDL Steeplejacks Ltd | Construction | 2024 |
| Ceble Limited | Financial services | 2017 |
| Cedars Steeplejack (Midlands) Limited | Construction | 1972 |
| Celadawn Limited | Wholesale & retail | 2013 |
| Celine Properties Limited | Real estate | 2020 |
| Cell Integrated Ltd | Administrative & support | 2021 |
| Cemar (Investments) Ltd | Professional & scientific | 2022 |
| CEN Idea Ltd | Information & communication | 2021 |
| CEN Idea Properties Ltd | Real estate | 2024 |