| Compass Complete Solutions Limited | Sandbach | 2013 |
| Compass Digital Solutions Ltd | Sandbach | 2013 |
| Compass Family Time Service Ltd | Sunderland | 2026 |
| Compass Fire Safety Ltd | Horsham | 2026 |
| Compass Skills Training Limited | Chorley | 2017 |
| Compassion First Care Ltd | Coventry | 2017 |
| Compassion First Consulting Ltd | Thames Ditton | 2025 |
| Compassionate Care 4 U Limited | Diss | 2025 |
| Compassionate Care Midlands Limited | West Midlands | 2024 |
| Compassionate Care Tamworth Ltd | West Midlands | 2024 |
| Compassionate Caring Ltd | London | 2026 |
| Compassiontc Limited | Colchester | 2020 |
| Competency Care Training UK Limited | London | 2026 |
| Competent Home Care Ltd | Gloucester | 2022 |
| Complete Care (Salisbury) Limited | Salisbury | 2025 |
| Complete Compliance Hub Ltd | Buckingham | 2024 |
| Complete Fire & Safety Limited | Doncaster | 2015 |
| Complete Fire Care Limited | Rugeley | 2023 |
| Complete Fire Protection Services Ltd | St. Leonards-On-Sea | 2024 |
| Complete Fire Safe Ltd | Coalville | 2024 |
| Complete Fire Safety UK Ltd | London | 2019 |
| Complete Fire Solutions Holdings Ltd | Mirfield | 2021 |
| Complete Home Care Sussex Ltd | Crawley | 2018 |
| Complete Safety Compliance Ltd | Nottingham | 2023 |
| Complex Care Group Ltd | Telford | 2020 |
| Complex’S Clarity Health Group Limited | Borehamwood | 2025 |
| Compliance and Care Training Limited | Birmingham | 2025 |
| Compliance and Payments Limited | Manchester | 2025 |
| Compliance Fire Ltd | Braintree | 2020 |
| Compliance Health Limited | Sheffield | 2018 |
| Compliance Oversight Services Limited | Huddersfield | 2023 |
| Compliance Training Services Limited | Manchester | 2005 |
| Compliancecare Ltd | Nuneaton | 2023 |
| Compliant Safety UK Ltd | Grimsby | 2018 |
| Complicity Limited | Gloucester | 2025 |
| Composurehq Community Interest Company | London | 2024 |
| Comprehensive EHC Services Ltd | Baston | 2017 |
| Comus Stalwart Services Limited | Bradford | 2021 |
| Concept Fire Protection Limited | Cardiff | 2022 |
| Concept Fire Services Ltd | New Milton | 2020 |
| Concept Fire Systems Limited | Chandlers Ford | 2008 |
| Concept Support & Accommodation Ltd | Alfreton | 2026 |
| Conecture Interventions Limited | Edinburgh | 2022 |
| Coneygar Consulting Limited | Cheltenham | 2013 |
| Confederation of International Talents Ltd | London | 2024 |
| Confluence Care Services Limited | Luton | 2024 |
| Conic Fire Safety Ltd | Bexley | 2022 |
| Connect (North Yorkshire) Limited | Scarborough | 2018 |
| Connect 5 Training Limited | Ellesmere | 2013 |
| Connect Complex Care Ltd | Bilston | 2023 |
| Connect Personnel Consultancy Ltd | West Bromwich | 2023 |
| Connect Stoke Ltd | Stoke-On-Trent | 2019 |
| Connexions for Ever Ltd | Whitley Bay | 2019 |
| Connor Bryan TM Ltd | Doncaster | 2022 |
| Connorfit Ltd | St. Neots | 2025 |
| Conprisa Limited | Norwich | 2015 |
| Conservative Friends of Lithuania | London | 2021 |
| Conservative Friends of the Baltic States UK Group | London | 2022 |
| Considered Solutions Limited | Plymouth | 2023 |
| Consilium Business Consultants Ltd | Warrington | 2018 |
| Consistent Quality Training Limited | Chesterfield | 2022 |
| Constant & Co (Bedford) Limited | Bedford | 2010 |
| Constant Fire and Electrical Ltd | East Sussex | 2005 |
| Constant Haven Ltd | London | 2022 |
| Construct Safety Ltd | Portsmouth | 2020 |
| Construction Concepts Ltd | Gatwick | 2024 |
| Construction Revolution Ltd | Croydon | 2026 |
| Construction Skills Training Solutions Ltd | Nottingham | 2014 |
| Consulat Impérial DU Tzar-An-Tzar Imperator Limited | Uxbridge | 2021 |
| Consult & Lead for Health Ltd Limited | London | 2025 |
| Consultancy & Design UK Ltd | Luxulyan | 2014 |
| Consumer Friend Ltd | Stevenage | 2022 |
| Continental Corporate Care Logistics Ltd | Pontypridd | 2022 |
| Contract Fire FM Service Limited | Chart Sutton | 2017 |
| Contractor BHM Limited | Rotherham | 2018 |
| Convergent Security Limited | London | 2003 |
| Conwy Fire Protection Ltd | Colwyn Bay | 2026 |
| Cookielove Ltd | Bradford | 2021 |
| Coombes Traffic Management Limited | Birmingham | 2019 |
| Coopergate Clinical Solutions Ltd | Fleet | 2026 |
| Copeland Consultants Limited | Morden | 2026 |
| Copperwood Compliance Ltd | Northampton | 2024 |
| Coracle Analysis Limited | Cambridgeshire | 2004 |
| Coram James Limited | London | 2011 |
| Cordial Safety Limited | Warminster | 2024 |
| Cordice Ltd | Rochester | 2025 |
| Cords Education Limited | Preston | 2022 |
| Core Care OH Ltd | Birmingham | 2025 |
| Core FRA Solutions Ltd | Ivybridge | 2025 |
| Core Vitality Ltd | Ashford | 2026 |
| Coreedge Learning Ltd | Huddersfield | 2025 |
| Corepath Trade N Service Limited | Oldham, United Kingdom | 2026 |
| Corevia Trading Services Limited | Oldham, United Kingdom | 2026 |
| Cormont Ltd | London | 2011 |
| Cornerstone Health Ltd | London | 2025 |
| Cornerstone Safety Limited | Sunderland | 2025 |
| Cornwall Medical Contracting Ltd | Truro | 2021 |
| Coronation Centre CIC | Bristol | 2023 |
| Corporate and Specialist Protection Limited | Cradley Heath | 2025 |
| Corporate Chroma Limited | London | 2025 |