| Church View Developments Limited | Agriculture & fishing | 2003 |
| Ciclo Magic Ltd | Arts & recreation | 2016 |
| Civil Estimating Services Ltd | Construction | 2007 |
| Clark James Limited | Administrative & support | 2006 |
| Classic Consultants Limited | Professional & scientific | 1990 |
| Classic Furniture (Binbrook) Limited | Wholesale & retail | 1996 |
| Claxby Wood Ltd | Agriculture & fishing | 2025 |
| Cleaner Peterborough Ltd | Administrative & support | 2022 |
| Cleaning Maintenance Supplies Limited | Administrative & support | 2003 |
| Clear Water Originals Ltd | Professional & scientific | 2026 |
| Clearance Shop Limited | Wholesale & retail | 2016 |
| Clearspout Services Ltd | Administrative & support | 2026 |
| Clive Polkey Consulting Ltd | Professional & scientific | 2025 |
| Clixby Biogas Limited | Energy | 2012 |
| CLY Optical Ltd | Health & social care | 2015 |
| Cmcraig Ltd | Professional & scientific | 2025 |
| Colebrook Dance Ltd | Arts & recreation | 2026 |
| Community Support and Outreach Dance (Csod) CIC | Arts & recreation | 2026 |
| Construction & Building Services (1994) Limited | Real estate | 1994 |
| Consulting Technical Management Services Limited | Information & communication | 2017 |
| Control ALT Elite Limited | Professional & scientific | 2025 |
| Coopers Wellness Ltd | Health & social care | 2022 |
| Cornhill (Caistor) Ltd | Real estate | 2022 |
| Cosmic Fireworks Ltd | Wholesale & retail | 2011 |
| Cote Hill Cheese Limited | Wholesale & retail | 2024 |
| County Chimney Specialists Limited | Construction | 2012 |
| County Court Solutions Limited | Professional & scientific | 2016 |
| County Industrial Doors Limited | Manufacturing | 1999 |
| Covell Brothers | Agriculture & fishing | 1960 |
| Cozy Lofts Limited | Extraterritorial | 2026 |
| Crackers, Desserts Ltd | Wholesale & retail | 2026 |
| Crepe Lucette Ltd | Hospitality | 2023 |
| Crofters Catering Company Limited | Hospitality | 2018 |
| Crossland Solutions Ltd | Professional & scientific | 2014 |
| Crossroad Store Ltd | Wholesale & retail | 2024 |
| Crowe Homes Limited | Construction | 2018 |
| Crown & Glory Hair Studio Ltd | Other services | 2012 |
| Crowstick Interiors Ltd | Manufacturing | 2024 |
| Cryotherapy Wellness Ltd | Other services | 2024 |
| Crystal Lake View Therapies Ltd | Health & social care | 2023 |
| CSB Delivery Ltd | Transport & logistics | 2022 |
| CT Pyro Group Limited | Professional & scientific | 2017 |
| CV Solutions Limited | Administrative & support | 2025 |
| Cystech Consulting Ltd | Information & communication | 2026 |
| D & J Collections Limited | Administrative & support | 2013 |
| D & R Woodall Limited | Agriculture & fishing | 2009 |
| D a Farms Limited | Agriculture & fishing | 2025 |
| D B LEE Limited | Construction | 2003 |
| D Grant Engineering Limited | Manufacturing | 2010 |
| D M Boyles Limited | Water & waste | 2003 |
| D Wells Electrical Ltd | Construction | 2019 |
| D Wells Property Ltd | Real estate | 2024 |
| D&B Healthcare Ltd | Wholesale & retail | 2018 |
| D. & B. Giles Limited | Construction | 1973 |
| D. W. East Limited | Wholesale & retail | 2003 |
| Dales Farm Limited | Real estate | 2018 |
| Dallan Consultancy Ltd | Professional & scientific | 2018 |
| Dallan Genetics Ltd | Agriculture & fishing | 2018 |
| DAN Decorating Ltd | Construction | 2019 |
| DAN Page Limited | Wholesale & retail | 2019 |
| Dane Court Projects Limited | Other services | 2004 |
| Dans Craft Beers Limited | Hospitality | 2021 |
| Data Helm Consulting Limited | Administrative & support | 2015 |
| David Brason Collections Limited | Professional & scientific | 2002 |
| David Buckle Limited | Extraterritorial | 2012 |
| Daxie Ltd | Professional & scientific | 2023 |
| DB EHS Solutions Ltd | Professional & scientific | 2024 |
| DBS Courier Services Ltd. | Transport & logistics | 2019 |
| DE Aston School Academy Trust | Education | 2011 |
| Deeley's Lincoln Limited | Wholesale & retail | 2025 |
| Deerness Structural Engineering and Design Limited | Professional & scientific | 2012 |
| Defining Future Media Ltd | Administrative & support | 2022 |
| Delta T Installations Limited | Construction | 2017 |
| Denton Pubs Ltd | Hospitality | 2025 |
| DES Smith & SON Limited | Construction | 2008 |
| Dialogue Translations Ltd | Professional & scientific | 2011 |
| Diamond Shine Extreme Clean Ltd | Construction | 2022 |
| Digital Legal Ventures Ltd | Professional & scientific | 2023 |
| Dino Property Limited | Real estate | 2019 |
| Diode Group Limited | Information & communication | 2019 |
| Disarmament Dynamics Limited | Administrative & support | 2016 |
| Divergently Ltd | Professional & scientific | 2026 |
| DJ Data Privacy UK Ltd | Professional & scientific | 2018 |
| DKC Projects Limited | Real estate | 2021 |
| DMC & Co Construction Ltd | Construction | 2019 |
| DMC Locum Services Ltd | Wholesale & retail | 2022 |
| Domerty Limited | Professional & scientific | 2007 |
| Doncaster Kitchens & Bedrooms Limited | Construction | 2019 |
| Dove Workshops and Co Limited | Professional & scientific | 2010 |
| DR Louisa Murray Ltd | Health & social care | 2026 |
| Draig Stack Limited | Wholesale & retail | 2026 |
| Drakes Farming Ltd | Agriculture & fishing | 2020 |
| Dregs PUB Group Limited | Hospitality | 2024 |
| Driving Sensation Limited | Arts & recreation | 2005 |
| DRP Online Trading Limited | Wholesale & retail | 2014 |
| Dryair Ltd | Energy | 2020 |
| DS Building and Joinery Limited | Construction | 2019 |
| DSB Farming and Contracting Limited | Agriculture & fishing | 2012 |
| DTA Temple Construction Limited | Construction | 2025 |
| DTM Tiling Ltd | Construction | 2021 |