| Chadwell Tyre & Service Ltd | Wholesale & retail | 2025 |
| Chadwick Wholesale Ltd | Wholesale & retail | 2025 |
| Chalk Castle Properties Limited | Real estate | 2018 |
| Chalkwell DRY Cleaners Ltd | Other services | 2019 |
| Chameleon Repair Ltd | Other services | 2021 |
| Change Life Property Ltd | Real estate | 2025 |
| Change-Up Consultancy Limited | Professional & scientific | 2015 |
| Channel & Fixings Ltd | Wholesale & retail | 2026 |
| Chapelstone Developments Limited | Construction | 2003 |
| Chapman & Sons Commercial Ltd | Real estate | 2025 |
| Chapman & Sons Developments Limited | Construction | 2016 |
| Chapter 24 Records Ltd. | Wholesale & retail | 2014 |
| Charfinity Limited | Professional & scientific | 2013 |
| Charfleets Fencing Limited | Construction | 2018 |
| Charfleets Landscaping Limited | Administrative & support | 2017 |
| Charfleets Maintenance Limited | Households | 1988 |
| Charis Provider Ltd | Information & communication | 2022 |
| Charlies Bar Brentwood Ltd | Hospitality | 2021 |
| Charthom Ltd | Hospitality | 2024 |
| Chelmsford Floor Screeding Limited | Construction | 2015 |
| Chereeleonaesthetics Ltd | Professional & scientific | 2025 |
| Cherish Family Services Ltd | Health & social care | 2024 |
| Cherleo Consultants Limited | Professional & scientific | 2015 |
| Cherry on the Top Limited | Real estate | 2009 |
| Chestwood Properties Ltd | Real estate | 2022 |
| Chinese Stars Ltd | Hospitality | 2023 |
| Chopp Limited | Other services | 2011 |
| Chopp NEX GEN Ltd | Other services | 2022 |
| CHP Architecture Limited | Professional & scientific | 2017 |
| CHP Property Ltd | Real estate | 2013 |
| CHP83 Ltd | Real estate | 2024 |
| Christa Elias Ltd | Information & communication | 2014 |
| Christiebella's Aesthetics Limited | Other services | 2023 |
| Christopher Sargent Associates Limited | Information & communication | 2001 |
| Chrystie Clark Ceilings Limited | Other services | 1997 |
| Chuckys Gym Ltd | Arts & recreation | 2022 |
| Churchridge Ltd | Construction | 2025 |
| Circuit Electrical Contracts Ltd | Construction | 2018 |
| Citizen One Ltd | Professional & scientific | 2025 |
| City Carpets & Flooring (Essex) Limited | Construction | 2013 |
| City Carpets & Flooring Limited | Wholesale & retail | 2025 |
| City Professional Services Ltd | Information & communication | 2007 |
| Civilarb Contractors Ltd | Administrative & support | 2021 |
| CJ Accommodations Limited | Real estate | 2024 |
| Cj's Bowling Limited | Arts & recreation | 2007 |
| CJ8 Limited | Real estate | 2021 |
| CJC Group Holdings Ltd | Financial services | 2022 |
| CJO Tech Ltd | Administrative & support | 2024 |
| CJP Digital Marketing Ltd | Wholesale & retail | 2016 |
| CJP Property Ltd | Construction | 2013 |
| Cjrs Installations Ltd | Construction | 2024 |
| CKE Repairs Ltd | Professional & scientific | 2021 |
| Ckmc Consulting Limited | Professional & scientific | 2024 |
| Cladding Master Ltd | Construction | 2019 |
| Claremont Facilities Ltd | Construction | 2018 |
| Claremont Property Maintenance Ltd | Construction | 2006 |
| Clarence Trust Co | Administrative & support | 2024 |
| Clarina Ltd | Wholesale & retail | 1998 |
| Clarity Boutique Ltd | Wholesale & retail | 2024 |
| Clark & Cole LLP | | 2025 |
| Class 1 Fruits Limited | Wholesale & retail | 2021 |
| Clayburn Brickwork & Construction Ltd | Construction | 2017 |
| Clear Signal Consulting Ltd | Professional & scientific | 2026 |
| Clearwater Homes CIC | Real estate | 2024 |
| Click & Collect Limited | Transport & logistics | 2013 |
| Cliff Edge Press Limited | Information & communication | 2018 |
| Cliffside Logistics Ltd | Construction | 2011 |
| Clinic 1 Academy Ltd | Education | 2021 |
| Clip & SON Ltd | Hospitality | 2025 |
| Clip Food Limited | Wholesale & retail | 2025 |
| Cloak Graphics Limited | Professional & scientific | 2011 |
| Cloverleaf Brickwork Limited | Construction | 2010 |
| Clubhouse Events Ltd | Professional & scientific | 2026 |
| CMF Joinery Limited | Construction | 2013 |
| CMR Consulting Group Ltd | Administrative & support | 2026 |
| CNM Gasworks Ltd | Other services | 2014 |
| CNR OZY Ltd | Real estate | 2026 |
| Coactive Ltd | Information & communication | 2023 |
| Cobham Hotel Limited | Hospitality | 2019 |
| Cobi Homes Limited | Construction | 2019 |
| Cockerel Construction Ltd | Construction | 2022 |
| Cockerpoodledoos Limited | Wholesale & retail | 2019 |
| Coco 09 Limited | Professional & scientific | 2009 |
| Codeblue Software Limited | Information & communication | 2025 |
| Coffee & Grub HUT Ltd | Manufacturing | 2024 |
| Coffee House Consulting Limited | Professional & scientific | 2023 |
| Colclough Electrical Contractors Ltd | Construction | 2009 |
| Cole & Cole Productions Limited | Professional & scientific | 2018 |
| Coley Court (505 High Road) RTM Company Limited | Households | 2020 |
| Collaborative Paraplanning Solutions Ltd | Financial services | 2022 |
| Collective Club Salon Ltd | Other services | 2025 |
| Collicom-It Limited | Information & communication | 2016 |
| Collins Architects Limited | Professional & scientific | 2020 |
| Collyer Consulting Global Ltd | Professional & scientific | 2013 |
| Colmar House Ltd | Real estate | 2024 |
| Colne Concrete Cutting Limited | Construction | 2016 |
| Colour N Cover Ltd | Manufacturing | 2016 |
| Coltec Building Services Ltd | Construction | 2015 |
| Coltec Letting & Development Ltd | Real estate | 2019 |
| Comfort Renewables Ltd | Professional & scientific | 2025 |