| Compass Aggregates Limited | Extraterritorial | 1952 |
| Compass Bidding Ltd | Administrative & support | 2025 |
| Compass Block Management Limited | Real estate | 2014 |
| Compass Care Services Ltd | Health & social care | 2023 |
| Compass Catering Services Limited | Extraterritorial | 1980 |
| Compass Cleaning Services Limited | Professional & scientific | 1927 |
| Compass Communication Solutions Ltd | Information & communication | 2016 |
| Compass Contracts UK Limited | Professional & scientific | 1971 |
| Compass Facility Solutions Ltd | Administrative & support | 2025 |
| Compass Mechanical Solutions Limited | Construction | 2025 |
| Compass P2P Solutions Limited | Administrative & support | 2023 |
| Compass Place (Birmingham) Management Company Limited | Households | 2005 |
| Compass Property Solutions (Midlands) Ltd | Real estate | 2011 |
| Compass Spon Street Management Limited | Households | 2010 |
| Compass Travel & Tourism Ltd | Administrative & support | 2026 |
| Compassion Care Recruitment Limited | Health & social care | 2025 |
| Compassionate Connexions CIC | Health & social care | 2023 |
| Compassionate Minds Ltd | Health & social care | 2019 |
| Compendium Director Limited | Professional & scientific | 2013 |
| Compendium GUF Limited | Professional & scientific | 2013 |
| Competent Electrical Ltd | Construction | 2016 |
| Competent Housing Ltd | Real estate | 2024 |
| Competitive Fire Solutions Limited | Manufacturing | 2015 |
| Compex Holdings Limited | Information & communication | 2019 |
| Compex IT Limited | Information & communication | 2016 |
| Compile (UK) Limited | Information & communication | 2011 |
| Complete Automotive Logistics Ltd | Transport & logistics | 2026 |
| Complete Building Control Ltd | Professional & scientific | 2008 |
| Complete Cardiology Limited | Health & social care | 2009 |
| Complete Care Smiles Limited | Health & social care | 2026 |
| Complete Care Support Limited | Health & social care | 2026 |
| Complete Care Training Solution UK Ltd | Education | 2013 |
| Complete Choice Care Services Limited | Health & social care | 2011 |
| Complete Cladding Facades Ltd | Construction | 2023 |
| Complete Clean Management Ltd | Administrative & support | 2009 |
| Complete Clinical Care Ltd | Health & social care | 2024 |
| Complete CNC Ltd | Wholesale & retail | 2018 |
| Complete Communication Holdings Limited | Financial services | 2015 |
| Complete Communications (UK) Ltd | Professional & scientific | 2000 |
| Complete Construction (Midlands) Limited | Construction | 2012 |
| Complete Construction Trades Ltd | Other services | 2017 |
| Complete Electrical Solutions (UK) Ltd | Other services | 2007 |
| Complete Fixing Solutions Holdings Limited | Construction | 2023 |
| Complete Fixing Solutions Limited | Construction | 2011 |
| Complete Home Improvements (Sutton Coldfield) Ltd | Construction | 2021 |
| Complete House Limited | Construction | 2013 |
| Complete Maintenance (Birmingham) Ltd | Administrative & support | 2023 |
| Complete Mortgage Solutions UK Limited | Financial services | 2000 |
| Complete Network Solution Limited | Information & communication | 2004 |
| Complete Packaging and Consumables Limited | Wholesale & retail | 2006 |
| Complete Payroll Ltd | Professional & scientific | 2016 |
| Complete Re-Upholstery Solutions Limited | Other services | 2014 |
| Complete Scanning Services Ltd | Administrative & support | 2017 |
| Complete Start Ltd | Administrative & support | 2019 |
| Complete Taxi Management UK Limited | Administrative & support | 2016 |
| Complete Well-Being Ltd | Other services | 2021 |
| Complete Your Home Ltd | Construction | 2024 |
| Completely Engineered Solutions Limited | Extraterritorial | 2017 |
| Complex Care Group Telford Ltd | Health & social care | 2026 |
| Complex Commercial Cleaning Ltd | Administrative & support | 2019 |
| Complex Housing Ltd | Real estate | 2024 |
| Compliance and Care Training Limited | Public administration | 2025 |
| Compliance Experts Ltd | Professional & scientific | 2022 |
| Compliance Facilities Management Ltd | Extraterritorial | 2019 |
| Compliance Housing Ltd | Real estate | 2026 |
| Compliance Legal Services Limited | Professional & scientific | 2018 |
| Complyhomes Ltd | Professional & scientific | 2025 |
| Component Workshop Limited | Information & communication | 2005 |
| Compound Arts Ltd | Arts & recreation | 2019 |
| Compound Hound Ltd | Manufacturing | 2023 |
| Comprehensive Management Consultants Limited | Professional & scientific | 1997 |
| Compressed Air Services Limited | Wholesale & retail | 2001 |
| Compsal Ltd | Extraterritorial | 2018 |
| Compton Acres DP Limited | Financial services | 2017 |
| Compton Court (Right to Manage) Company Limited | Households | 2005 |
| Compton Manor Limited | Health & social care | 2012 |
| Compttec Limited | Education | 2008 |
| Computer Alligator Limited | Wholesale & retail | 2023 |
| Computer and Data Services Management Ltd | Wholesale & retail | 2019 |
| Computer and Phone Centre Ltd | Wholesale & retail | 2012 |
| Computer Birds Limited | Information & communication | 2025 |
| Computer Science Limited | Information & communication | 2004 |
| Computer Science Tutors UK Ltd | Education | 2025 |
| Computer Software Holdings Limited | Financial services | 2006 |
| Computer Specialist Ltd | Wholesale & retail | 2018 |
| Computer Technologies Plus Limited | Information & communication | 2003 |
| COMPUTERS4ALL (UK) Limited | Other services | 2014 |
| Computime IT Solutions Ltd | Information & communication | 2010 |
| Computrade Ltd | Professional & scientific | 1996 |
| Compuzone IT Ltd | Wholesale & retail | 2022 |
| COMR4D3 Ltd | Construction | 2025 |
| Comres Management LLP | | 2020 |
| Comstead (Mechanical Services) Limited | Financial services | 2004 |
| Comtech Impex Limited | Wholesale & retail | 2024 |
| Comteck Solutions Limited | Professional & scientific | 2019 |
| Comunicoms Ltd | Information & communication | 2021 |
| Comutiny Ltd | Agriculture & fishing | 2018 |
| Comux UK Ltd | Information & communication | 2012 |
| COMWAT-102 Limited Partnership | | 2017 |
| COMWAT-104 Limited Partnership | | 2018 |