| Compass Timber Company Limited | Berkhamsted | 1991 |
| Compass Trailers Ltd | Lewes | 2011 |
| Compass Window Cleaning NW Ltd | Bolton | 2025 |
| Compass Yacht Tenders Limited | Fareham | 2013 |
| Compassion Works Ltd | Hereford | 2021 |
| Compassionate Kitchen Ltd | Leeds | 2020 |
| Compatible Cards Limited | London | 2014 |
| Compbrake Motorsport Ltd | Wigan | 2011 |
| Compchess Automation Engineers Ltd | Derby | 2025 |
| Compdoor Limited | Alfreton | 2021 |
| Compeat Limited | Truro | 2025 |
| Compec Electrical Installations Ltd | Warrington | 2018 |
| Compel Limited | Stockport | 2011 |
| Compere Systems Limited | Merseyside | 1989 |
| Competition Classics Ltd. | Uckfield | 2016 |
| Competition Fabrications Ltd. | Attleborough | 2017 |
| Competitive Fire Solutions Limited | Birmingham | 2015 |
| Compilation Group Limited | Stockton-On-Tees | 2023 |
| Complete 3D Prints Ltd | Skelmersdale | 2026 |
| Complete Access (Engineering & Services) Limited | Hull | 2004 |
| Complete Air Supplies Ltd | Glossop | 2019 |
| Complete Aluminium Solutions Limited | Rugeley | 2021 |
| Complete Aluminium Systems Ltd | Gloucester, | 2011 |
| Complete Apparel Ltd | Chichester | 2022 |
| Complete Automotive Repair Solutions Limited | St. Albans | 2025 |
| Complete Boiler Care Ltd | Sturminster Newton | 2022 |
| Complete Bowling Services Limited | Leicester | 2008 |
| Complete Branding Limited | Palmers Green | 2013 |
| Complete Branding, Print & Signage Solutions Ltd | Glasgow | 2026 |
| Complete Building Merchants Ltd | Wigan | 2019 |
| Complete Business Supplies Limited | Alnwick | 2008 |
| Complete Camper Repair Ltd | Andover | 2023 |
| Complete Car Care Ltd | Evesham | 2020 |
| Complete Caravan Solutions Ltd | Halstead | 2010 |
| Complete Carpentry & Joinery Ltd | London | 2015 |
| Complete Carpentry and Bespoke Cabinetry Ltd | Biggin Hill | 2024 |
| Complete Carpentry Shropshire Ltd | Kingswinford | 2023 |
| Complete Carpentry Solutions Limited | Monmouth | 2019 |
| Complete Catering Projects Ltd | Northampton | 2021 |
| Complete Co-Packing Services Limited | Mountain Ash | 2015 |
| Complete Coffee & Bakery Limited | Liverpool | 2023 |
| Complete Combustion Limited | Dunstable | 2000 |
| Complete Control Services London Limited | Dunstable | 2012 |
| Complete Conveyor Projects Limited | Nottingham | 2017 |
| Complete Cooling Systems Limited | Kent | 1984 |
| Complete Core Business Solutions Limited | London | 2006 |
| Complete Dairy Services Ltd | Middlewich | 2022 |
| Complete Dairy Solutions Ltd | Altrincham | 2026 |
| Complete Dental Solutions UK Ltd | Liverpool | 2016 |
| Complete Doorset Solutions Install Ltd | Bexley | 2022 |
| Complete Doorset Solutions Limited | Horsham | 2016 |
| Complete Drawers Solution Ltd | Northampton | 2019 |
| Complete Electronics Limited | Milton Keynes | 2006 |
| Complete Elevator Solutions Ltd | Dorchester | 2022 |
| Complete Engine Services Limited | Exeter | 2022 |
| Complete Engineering Solutions (Northwest) Ltd | Fleetwood | 2011 |
| Complete Engineering Solutions Scotland Ltd | Cowdenbeath | 2025 |
| Complete English Kitchens Ltd | Leigh-On-Sea | 2008 |
| Complete Fabrication Ltd | Cambridge | 1998 |
| Complete Fabrication Solutions Ltd | Motherwell | 2020 |
| Complete Fire Door Solutions Ltd | Plymouth | 2025 |
| Complete Framing Limited | Peterborough | 2009 |
| Complete Garden Solutions Ltd | Manchester | 2024 |
| Complete Handling Limited | Stoke On Trent Staffordshire | 1998 |
| Complete Healthy Skin Ltd | London | 2026 |
| Complete Hire Services Limited | Hessle | 2004 |
| Complete Hub Technologies Limited | Rugby | 2015 |
| Complete Hydraulic & Engineering Solutions Limited | Chatham | 2012 |
| Complete Hydraulic Solutions Limited | Merthyr Tydfil | 2021 |
| Complete Industrial Solutions Limited | Banbridge | 2021 |
| Complete Ions Limited | Witney | 2003 |
| Complete Irrigation Systems Limited | Gloucester | 2004 |
| Complete Joinery NI Ltd | Belfast | 2019 |
| Complete Lean Tube Limited | Nottingham | 2018 |
| Complete Lift Projects Ltd | Wellingborough | 2016 |
| Complete Lighting Services Limited | Basingstoke | 1996 |
| Complete Logic Ltd | Woolton Hill | 2023 |
| Complete Machine Services Ltd | Botcheston | 2012 |
| Complete Machining Services Limited | Hull | 2001 |
| Complete Maintenance Solutions Limited | Washington | 2008 |
| Complete Manufacturing Services Limited | Pinxton | 2005 |
| Complete Manufacturing Solutions Limited | Bolton | 2008 |
| Complete Marine Solutions Ltd | Bournemouth | 2016 |
| Complete Miniature Railways Limited | Anglesey | 2002 |
| Complete Packaging (Midlands) Ltd | Long Eaton | 2015 |
| Complete Packaging Limited | Aylesbury | 1998 |
| Complete Packaging Services Limited | Halifax | 1993 |
| Complete Pixel Solutions Ltd | Uxbridge | 2022 |
| Complete Plant Maintenance Engineering Limited | Manchester | 1987 |
| Complete Print Services Ltd | London | 2016 |
| Complete Racking Solutions UK Ltd | Nottingham | 2017 |
| Complete Refrigeration Services Ltd | Hull | 2011 |
| Complete Safety Systems Limited | Northampton | 2003 |
| Complete Serv UK Ltd | Harrow | 2025 |
| Complete Service Company (UK) Limited | Ely | 2013 |
| Complete Service Management Ltd | Bradford | 2002 |
| Complete Shutter Services Limited | Rotherham | 1993 |
| Complete Sign Experience Limited | Mansfield | 1994 |
| Complete Sign Solutions Limited | Camberley | 2006 |
| Complete Signs Ltd | Bournemouth | 2020 |