| Buckley Building Services (UK) Ltd | Construction | 2014 |
| Bucks Concrete Limited | Manufacturing | 2019 |
| Buff Beards Ltd | Manufacturing | 2025 |
| Build Perfect Ltd | Construction | 2025 |
| BUILD4U Property Management Ltd | Real estate | 2025 |
| Builder Cat Limited | Construction | 2018 |
| Bumbles Car Wash Ltd | Administrative & support | 2025 |
| Burbergo Ltd | Manufacturing | 2021 |
| Burgess Barn Studios Limited | Arts & recreation | 2018 |
| Burleigh Lodge Developments Ltd | Construction | 2022 |
| Burleigh Nursery Developments Ltd | Construction | 2019 |
| Burlington Place 2 (Foxton) Management Company Limited | Households | 2020 |
| Burst Drink Limited | Manufacturing | 2014 |
| Buse Restaurant Ltd | Hospitality | 2025 |
| Bush Hill Park Fish Company Limited | Hospitality | 2025 |
| Bush Mechanical Engineering Limited | Construction | 2014 |
| Business Loans London Limited | Professional & scientific | 2017 |
| Busra Limited | Hospitality | 2015 |
| Buxton Models Limited | Other services | 2022 |
| Buy ANY Cake Ltd | Wholesale & retail | 2020 |
| Buyers Line Direct Limited | | 2007 |
| BWH Trading Limited | Wholesale & retail | 2023 |
| C & G Plastering Group Ltd | Financial services | 2018 |
| C & G Plastering Limited | Construction | 1986 |
| C and D Construction and Developments Ltd | Construction | 2018 |
| C and D Developments & Investments Ltd | Real estate | 2020 |
| C and D Investment Holdings Ltd | Real estate | 2021 |
| C Arrowsmith Property Ltd | Real estate | 2015 |
| C F B Contracts Ltd | Water & waste | 2020 |
| C Muyendesi Ltd | Health & social care | 2016 |
| C O Home Solutions Ltd | Real estate | 2017 |
| C Sharman Electrical Ltd | Construction | 2015 |
| C W Mason Ltd | Manufacturing | 2024 |
| C&L Skips London Limited | Water & waste | 2018 |
| C.A.E. Diesel Limited | Wholesale & retail | 1976 |
| C.L.D. Services Limited | Administrative & support | 1974 |
| C.R.E.A International Ltd | Wholesale & retail | 2024 |
| C.T. Paving Ltd | Construction | 2015 |
| C3 Constructions and Consulting Limited | Construction | 2018 |
| Caba. Interior Studio Ltd | Professional & scientific | 2023 |
| Cacioppo Property Investments Ltd | Real estate | 2023 |
| CAD Luxury Homes Ltd | Manufacturing | 2024 |
| Cadogan Homes Limited | Construction | 1996 |
| Caesars Cakes Ltd | Wholesale & retail | 2024 |
| Cafe Loco (Bury Market) Limited | Hospitality | 2025 |
| Cakeaway Enterprises Ltd | Manufacturing | 2026 |
| Calendar Wonderland Limited | Manufacturing | 2013 |
| Callalilly Ltd | Other services | 2018 |
| Camberwell Catering 1975 Limited | Hospitality | 2026 |
| Cambium Square (Cambourne) Management Company Limited | Households | 2025 |
| Cambridge Investment Partnership LLP | | 2018 |
| Campion & Hare (Petworth) Limited | Wholesale & retail | 2024 |
| Campion & Hare Limited | Real estate | 2024 |
| CAN Cleaning Ltd | Administrative & support | 2020 |
| Canalside (Oxford) Management Company Limited | Households | 2023 |
| Candyboxbeauty Ltd | Wholesale & retail | 2025 |
| Cane Catering Ltd | Hospitality | 2020 |
| Cani Construction Ltd | Construction | 2018 |
| Canram Ltd | Wholesale & retail | 2026 |
| Cansu 29 Ltd | Wholesale & retail | 2021 |
| CAP Waste Group Ltd | Water & waste | 2025 |
| Capital Building Company (UK) Ltd | Construction | 2013 |
| Capital TEE Ltd | Arts & recreation | 2022 |
| Capital Waste-Not C.I.C. | Water & waste | 2026 |
| Capsid Biotechnology Ltd | Professional & scientific | 2024 |
| Car City Service Ltd | Wholesale & retail | 2025 |
| Careplan Services Limited | Professional & scientific | 2022 |
| Carey Hall Preschool Limited | Education | 2017 |
| Carlton Controls Limited | Manufacturing | 1989 |
| Carol's of Bishops Stortford Limited | Wholesale & retail | 2001 |
| Carpentry by A&M Limited | Manufacturing | 2021 |
| Carpus Delivery Ltd | Transport & logistics | 2023 |
| Cars Plus Trader Limited | Wholesale & retail | 2020 |
| Carter Remy Estate Agents (South East) Ltd | Real estate | 2023 |
| Carter Remy Estates Ltd | Real estate | 2021 |
| Cartigo Ltd | Water & waste | 2020 |
| Cartiwaste Ltd | Water & waste | 2021 |
| Cartorresi Limited | Wholesale & retail | 2016 |
| Cartzio Trading Ltd | Wholesale & retail | 2025 |
| CAS Car Hire Limited | Wholesale & retail | 2021 |
| Cascade Property Investments Ltd | Real estate | 2021 |
| Casim Anthony Limited | Real estate | 2017 |
| Cass & Penn Properties Ltd | Real estate | 2024 |
| Castable Resin Ltd | Wholesale & retail | 2018 |
| Cat Hill Chiropractic Clinic (Barnet) Ltd | Health & social care | 2007 |
| Cater-Sen Limited | Wholesale & retail | 2016 |
| Catering for Everyone Ltd | Hospitality | 2021 |
| Catering Leasing Solutions Limited | Hospitality | 2020 |
| Catherine Tough Wholesale Ltd | Wholesale & retail | 2023 |
| Cavus Oglu Ltd | Real estate | 2020 |
| CB Motors Essex Ltd | Wholesale & retail | 2022 |
| CB Party Ltd | Manufacturing | 2018 |
| CB Refresh Ltd | Wholesale & retail | 2025 |
| CBD Biotech Limited | Wholesale & retail | 2018 |
| CBD Business Limited | Wholesale & retail | 2018 |
| CDC OPS Consulting Ltd | Professional & scientific | 2024 |
| CDK Motors Ltd | Wholesale & retail | 2025 |
| Ceilex Ltd | Construction | 2026 |
| Celiik Properties Ltd | Real estate | 2025 |
| Celik Hayta Limited | Hospitality | 2026 |