| Confidence Club Coaching Ltd | Arts & recreation | 2021 |
| Confident Freight Forwarding Limited | Transport & logistics | 2014 |
| Confident Global Tech Ltd | Information & communication | 2026 |
| Confido Consult Ltd | Administrative & support | 2022 |
| Conflate Limited | Information & communication | 2014 |
| Conflict&Resolution.Uk Ltd | Education | 2026 |
| Conform NW Limited | Construction | 2016 |
| Conglomerate Ltd | Construction | 2019 |
| Conifer Court Management Company Limited | Households | 1982 |
| Coniston House RTM Company Ltd | Households | 2025 |
| Conjugate Sports Performance Ltd | Arts & recreation | 2023 |
| Conli Limited | Real estate | 2016 |
| Conlin Properties Ltd | Construction | 2016 |
| Conmigu Ltd | Professional & scientific | 2021 |
| Connect 2 Protect Limited | Financial services | 2025 |
| Connect 4.0 Ltd | Information & communication | 2018 |
| Connect Academy Limited | Education | 2019 |
| Connect and Grow Ltd | Real estate | 2025 |
| Connect Car Finance Ltd | Administrative & support | 2016 |
| Connect Change Consultants Limited | Professional & scientific | 2015 |
| Connect Concierge Group Limited | Administrative & support | 2026 |
| Connect Construction (NW) Ltd | Construction | 2021 |
| Connect Consultancy (NW) Ltd | Professional & scientific | 2020 |
| Connect Dance Academy Limited | Arts & recreation | 2020 |
| Connect Design & Build Ltd | Construction | 2018 |
| Connect Energy Network Solutions Ltd | Construction | 2019 |
| Connect Fitness and Mobility Ltd | Arts & recreation | 2026 |
| Connect Internet Solutions Holdings Limited | Financial services | 2025 |
| Connect Internet Solutions Limited | Information & communication | 2002 |
| Connect Investments Ltd. | Real estate | 2020 |
| Connect Parcels (NW) Ltd | Transport & logistics | 2026 |
| Connect Umbrella Limited | Professional & scientific | 2019 |
| Connecta Family Network Ltd | Health & social care | 2026 |
| Connected Circles Ltd | Administrative & support | 2025 |
| Connected Futures CIC | Education | 2026 |
| Connectioning Ltd | Professional & scientific | 2025 |
| Connectnlink Ltd | Information & communication | 2024 |
| Conneely Ltd | Construction | 2024 |
| Connell Associates LLP | | 2018 |
| Connell Care Ltd | Health & social care | 2023 |
| Connell Law Limited | Professional & scientific | 1982 |
| Connella Ltd | Construction | 2009 |
| Connemara Consulting Limited | Professional & scientific | 2009 |
| Connex Electrical Limited | Construction | 2017 |
| Connexus Training Limited | Other services | 2023 |
| Conniston Limited | Extraterritorial | 2011 |
| Connolly and Riley Limited | Professional & scientific | 2015 |
| Connollys General Builders Limited | Construction | 2008 |
| Connor Bates Hair Ltd | Other services | 2022 |
| Connor Coaching Ltd | Arts & recreation | 2021 |
| Connor Consulting Engineers Limited | Construction | 2005 |
| Connor Essery Ltd | Transport & logistics | 2025 |
| Connor Global Properties Ltd | Real estate | 2023 |
| Connor's Building & Restoration Ltd | Manufacturing | 2000 |
| Connordavidstanger Ltd | Health & social care | 2025 |
| Connors Building Limited | Construction | 2019 |
| Connors Estate Group Limited | Real estate | 2025 |
| Connors Group Ltd | Financial services | 2019 |
| Connors Property Developments LLP | | 2013 |
| Connorscleaning Limited | Administrative & support | 2025 |
| Conor M Trading Ltd | Wholesale & retail | 2025 |
| Conox Holdings Limited | Financial services | 2019 |
| Conox Mechanical Services Limited | Construction | 2008 |
| Conpar Limited | Wholesale & retail | 1987 |
| Conquista Cycling Club Limited | Information & communication | 2013 |
| Conrad UK Homes Ltd | Real estate | 2017 |
| Conroystoneproperty Ltd | Construction | 2026 |
| Consbrix Developments Limited | Real estate | 1964 |
| Conscious Clearance and Removals Services CIC | Transport & logistics | 2026 |
| Conscious Detox Ltd | Other services | 2019 |
| Conscious Energy Ltd | Construction | 2019 |
| Conscious Roofing Ltd | Construction | 2025 |
| Conscious Utilities Ltd | Professional & scientific | 2015 |
| Consciously Creative Limited | Professional & scientific | 2021 |
| Consciously Living Limited | Real estate | 2025 |
| Consec Facilities Limited | Administrative & support | 2015 |
| Conservation Cornwall Limited | Real estate | 2024 |
| Conservation Gilding Ltd | Arts & recreation | 2012 |
| Conserve Engineering Solutions UK Ltd | Professional & scientific | 2024 |
| Consolerepairliverpool Limited | Other services | 2025 |
| Consolux Holdings Ltd | Financial services | 2018 |
| Consolux Management Ltd | Professional & scientific | 2021 |
| Consolux Sustainabilty Ltd | Construction | 2018 |
| Consortia Group Holdings Ltd | Financial services | 2021 |
| Consortia Integrated Services Ltd | Construction | 2009 |
| Consortia Propco Limited | Construction | 2020 |
| Consortia Property Holdings Ltd | Financial services | 2021 |
| Constandinou Williams Group Ltd | Financial services | 2019 |
| Constant Trans Ltd | Wholesale & retail | 2017 |
| Constellation Care Services Ltd | Hospitality | 2022 |
| Constellation Cleaning Services Ltd | Administrative & support | 2025 |
| Constellation Marketing Solutions Limited | Administrative & support | 2022 |
| Constellation Property Services Ltd | Construction | 2024 |
| Construct-It Consulting Limited | Professional & scientific | 2019 |
| Constructag Limited | Construction | 2023 |
| Construction and Demolation Limited | Construction | 2023 |
| Construction Company B Limited | Construction | 2025 |
| Construction Consultancy NW Limited | Professional & scientific | 2025 |
| Construction Depot Limited | Administrative & support | 2025 |
| Construction Management NWP Limited | Construction | 2022 |