| Active Design Limited | Milton Keynes | 1991 |
| Active Design Solutions Limited | Bristol | 2012 |
| Active Designs & Ideas Limited | Wigton | 2002 |
| Active Edge Perfromance Ltd | Northwich | 2025 |
| Active Electrical Motion Limited | Marlow | 2014 |
| Active Elite Limited | Liverpool | 2025 |
| Active EMS Ltd | Bury | 2021 |
| Active Engineering (GB) Limited | Bucks | 2003 |
| Active Fire & Security (UK) Limited | Bideford | 2008 |
| Active Fitness Ltd | Dukinfield | 2023 |
| Active Flow Controls Limited | Andover | 2010 |
| Active Food Systems Limited | St. Neots | 1999 |
| Active Garden Limited | Leominster | 2004 |
| Active Grow Ltd | Lincoln | 2020 |
| Active Handling Systems Limited | Kidderminster | 2010 |
| Active Heating Services Ltd | Newbury | 1999 |
| Active Hydraulics (UK) Ltd | Keighley | 2007 |
| Active Ideas Ltd | Newark | 2005 |
| Active IQ Wear Ltd | Ilford | 2024 |
| Active Kinetic 1 Ltd | Gravesend | 2023 |
| Active Line Therapy Ltd | Glastonbury | 2024 |
| Active Linx Ltd | Peterborough | 1999 |
| Active Load International Limited | Reading | 2018 |
| Active Maintenance Calderdale Limited | Sowerby Bridge | 2022 |
| Active Market & Partners Limited | London | 2025 |
| Active Medical Technology Limited | Lancashire | 1996 |
| Active Metal Works Limited | Edmonton | 2024 |
| Active Metals Limited | Sheffield | 1984 |
| Active Moulds Limited | Estate Dinnington, Sheffield | 2003 |
| Active Office Seating Limited | Hornchurch | 2003 |
| Active Pipeline Refurbishment Technologies Ltd | Bolton | 2003 |
| Active Print Services Limited | Northwood Hills | 2009 |
| Active Print Solutions Limited | Leeds | 2003 |
| Active Research Limited | Poole | 1996 |
| Active Robots Limited | Bradley Stoke | 2003 |
| Active Scenery Ltd | Northampton | 2026 |
| Active Sensors Limited | Christchurch | 1993 |
| Active Signs (Minehead) Limited | Minehead | 2008 |
| Active Signs and Designs Ltd | Basildon | 2018 |
| Active Silicon Limited | Redditch | 1988 |
| Active Sports Direction Limited | Colchester | 2010 |
| Active Springs Studley Ltd | Redditch | 2022 |
| Active Surfaces Inc UK Ltd | London | 2026 |
| Active Tackle Limited | Ramsgate | 2013 |
| Active Tools Limited | Reading | 2003 |
| Active Trade Frames Ltd | Tewkesbury | 2018 |
| Active Trading Ltd | Enfield | 2019 |
| Active Transducer Research Limited | York | 2017 |
| Active Transfer Limited | Horsforth | 2023 |
| Active UK Security Limited | Wolverhampton | 2015 |
| Active Virtue Ltd | Coventry | 2023 |
| Active Windows & Doors Ltd | Washington | 2010 |
| Active-Display Solutions Ltd | Thatcham | 2017 |
| Active-Pcb Solutions Limited | Reading | 1997 |
| ACTIVE8 Managed Technologies Limited | Newark | 2013 |
| Activedesk Limited | Liverpool | 2021 |
| Activinsights Limited | Kimbolton | 2008 |
| Activiz Ltd | Llandudno | 2020 |
| Activon Impex Limited | Belfast | 2026 |
| Actmr Creations & Productions Ltd | London | 2022 |
| Acto Media Ltd | London | 2019 |
| Acto Print Ltd | London | 2005 |
| Actolia Ltd | London | 2024 |
| Acton & Acton Limited | Rochdale | 1985 |
| Acton CUT Limited | London | 2008 |
| Acton Engineering (Norfolk) Limited | Downham Market | 2024 |
| Acton Finishing Limited | West Midlands | 2002 |
| Acton Haigh Ltd | Cossington | 2009 |
| Acton Security Ltd | St Ives | 2009 |
| Acton Stationers & Printers Limited | London | 1976 |
| Actron Ltd | Honiton | 1974 |
| Acts NOT Facts Ltd | London | 2014 |
| ACTS37 Limited | London | 2017 |
| Actsmarine Ltd | Glasgow | 2021 |
| Actua Systems Limited | Chippenham | 2012 |
| Actual Property Limited | Glasgow | 2010 |
| Actual Reality Limited | Southampton | 2026 |
| Actuated Limited | Bristol | 2008 |
| Actuated Solutions Limited | Bognor Regis | 2003 |
| Actuation Engineering Ltd | Chichester | 2001 |
| Actuator Electronic Designs Ltd | Cheltenham | 2012 |
| Actuator Repair Services Limited | Thetford | 2014 |
| ACU Group Limited | Bristol | 2018 |
| ACU Print Limited | Peterborough | 2000 |
| Acu-Flow Limited | Glasgow | 2019 |
| Acua Ocean Limited | Plymouth | 2020 |
| Acuity Intelligent Spaces UK Limited | London | 2024 |
| Acula Creations Limited | Folkestone | 2013 |
| Aculab Ltd | Reading, Berkshire | 1978 |
| Acumak Ltd | Basingstoke | 2007 |
| Acumedic Limited | | 1985 |
| Acumen CNC Ltd | Thetford | 2017 |
| Acumen Electronics Ltd | Newport | 2025 |
| Acumen Industrial Services Limited | Hereford | 2007 |
| Acumex Machining Group Ltd | Beverley | 2025 |
| Acurable Limited | London | 2016 |
| Acushnet Europe Ltd | St Ives | 1975 |
| Acuson United Kingdom Ltd. | Camberley | 2021 |
| Acutaas Healthcare Limited | Loughborough | 2026 |
| Acute Elevators North Ltd | Rochester | 2023 |