| Contoso (UK) Ltd | Information & communication | 2014 |
| Cooked and Co (York) Ltd | Real estate | 2020 |
| Cooked Films Ltd | Information & communication | 2022 |
| Coolant Control Limited | Administrative & support | 2003 |
| Coolant Management Services Limited | Wholesale & retail | 1989 |
| Coombs Catering Partnership Limited | Hospitality | 2008 |
| Coombs Group Ltd | Hospitality | 2016 |
| Cooper Lennard Homes Ltd | Construction | 2025 |
| Core Aquatics Ltd. | Arts & recreation | 2015 |
| Core Classics Ltd | Wholesale & retail | 2019 |
| Corevestor Properties Limited | Real estate | 2018 |
| Cosimo Holdings Limited | Professional & scientific | 2019 |
| Cosmetec Limited | | 1987 |
| Cosmic Decks UK Ltd | Wholesale & retail | 2026 |
| Cotesbach Educational Trust Limited | Education | 2006 |
| Cotesbach Gardens C.I.C. | Agriculture & fishing | 2015 |
| Council for Voluntary Service Northampton and County | Other services | 1994 |
| Country Properties (WGC) Lettings Limited | Real estate | 2008 |
| Countryside Construction Services Ltd | Construction | 2019 |
| County Asset Finance Limited | Financial services | 1995 |
| County Commercials & Cars Ltd | Wholesale & retail | 2025 |
| County Finance Group Limited | Financial services | 2001 |
| County Home and Garden Limited | Administrative & support | 2009 |
| Covac Limited | Professional & scientific | 1996 |
| Covent Garden Imaging Ltd | Health & social care | 2026 |
| Coventry Christmas Market Ltd | Hospitality | 2023 |
| Coventry Digs Limited | Real estate | 2023 |
| Covertec Structures Ltd | Manufacturing | 2003 |
| Cowley-Horn Diver Medicals Ltd | Health & social care | 2025 |
| CPB Electrical Installations Limited | Construction | 2026 |
| CPS Recruitment Limited | Administrative & support | 2009 |
| CPS Project Management Limited | Administrative & support | 2009 |
| CPY Investments Limited | Real estate | 2017 |
| CQ Group Ltd | Construction | 2024 |
| CR Properties (Leics) Ltd | Real estate | 2021 |
| Cr.Surfacing Ltd | Construction | 2021 |
| Craig-Lloyd Limited | Construction | 1967 |
| Creamworks Ice Cream Ltd | Hospitality | 2025 |
| Creative Freight Events Ltd | Transport & logistics | 2018 |
| CREATIVE4 Ltd | Information & communication | 2016 |
| Credit Risk Lifecycle Ltd | Professional & scientific | 2025 |
| Creo Recruitment Ltd | Administrative & support | 2019 |
| CRK Motor Insurance Services Limited | Financial services | 2003 |
| Cross Counties Radio | Information & communication | 2010 |
| Crossfit Lutterworth Ltd | Arts & recreation | 2015 |
| Crossley Franks Consulting Ltd | Information & communication | 2016 |
| Crowfoot & Co Accountants Ltd | Professional & scientific | 2017 |
| Croydon Tattoo Limited | Other services | 2018 |
| Crozier Fine Arts Limited | Transport & logistics | 1975 |
| CRS Recovery Services Limited | Transport & logistics | 2021 |
| Crystal Cover Limited | Financial services | 2015 |
| CS Digital Engineering Ltd | Professional & scientific | 2022 |
| CS Hall Ltd | Wholesale & retail | 2025 |
| Csdn Homes Ltd | Other services | 2015 |
| CSF Medical Communications Ltd | Manufacturing | 1999 |
| CT Electrical and Energy Solutions Limited | Construction | 2012 |
| CT Practice Ltd | Health & social care | 2025 |
| Cube Corporate Awards Ltd | Professional & scientific | 2011 |
| Cubic Mushroom Ltd. | Information & communication | 2011 |
| Cufflin Court Ltd | Real estate | 2017 |
| CYO Seeds (Midlands) Limited | Agriculture & fishing | 2005 |
| CYS Properties Ltd | Real estate | 2020 |
| D & M Motors Limited | Wholesale & retail | 1997 |
| D & S Swimming Pools Limited | Professional & scientific | 2005 |
| D a Motors (Lutterworth) Ltd | Wholesale & retail | 2018 |
| D B George Ltd | Public administration | 2026 |
| D C Bouch Limited | Other services | 2010 |
| D P Events Management Limited | Professional & scientific | 2006 |
| D Theta Ltd | Professional & scientific | 2007 |
| D&A Powell Ltd | Professional & scientific | 2020 |
| D&Dc Data & Technology Limited | Administrative & support | 2016 |
| D&M Express Ltd | Transport & logistics | 2019 |
| D.W. Hicks Building Company Limited | Construction | 1979 |
| D4R Holdings Limited | Financial services | 2006 |
| Dacs Document Storage Limited | Extraterritorial | 2011 |
| Dacs Office Solutions Limited | Administrative & support | 2007 |
| Dalby and Co. Limited | Real estate | 1996 |
| DAM Fast Ltd | Construction | 2017 |
| Danby Property Ltd | Real estate | 2020 |
| Dandell Limited | Health & social care | 2020 |
| Danuseduk Limited | Wholesale & retail | 2025 |
| Darrenpalm Limited | Administrative & support | 1979 |
| Dartsunlimited Ltd | Wholesale & retail | 2025 |
| Darwood Construction Limited | Other services | 2010 |
| Data-Shield Ltd | Information & communication | 2005 |
| Datastream Supplies Limited | Extraterritorial | 1983 |
| Davant Surface Coatings Limited | Wholesale & retail | 1976 |
| Dave's Treasure Trove Limited | Wholesale & retail | 1994 |
| David Booth Consultancy Limited | Construction | 2005 |
| David King Electronics Limited | Manufacturing | 2002 |
| David Longhurst Haulage Limited | Transport & logistics | 1997 |
| David Magill Limited | Professional & scientific | 2015 |
| David Ross Fabrications Limited | Manufacturing | 2000 |
| David Vintiner Ltd | Professional & scientific | 2015 |
| Dayflex Ltd | Information & communication | 2025 |
| Dayflexuk Ltd | Administrative & support | 2025 |
| DB Services (Wolverhampton) Ltd | Professional & scientific | 2012 |
| DBS Kitchen Trailer Hire Ltd | Hospitality | 2025 |
| DBW Property Limited | Real estate | 2023 |
| DC Media Advisory Limited | Administrative & support | 2018 |