| Air Products Public Limited Company | Chertsey | 1909 |
| Air Pumping Limited | Chelmsford | 2000 |
| Air Reach Limited | Maidstone | 2015 |
| Air Repair Limited | Fordingbridge | 2014 |
| Air Rescue Systems Ltd | Motherwell | 2015 |
| Air Revolution Technologies UK Ltd | Port Talbot | 2020 |
| Air Sampling Instruments Limited | Oldham | 2004 |
| Air Science Technologies Ltd | Downholland | 2004 |
| Air Seating (Holdings) Limited | Kingswinford | 2015 |
| Air Seating Limited | Kingswinford | 2007 |
| Air Sentry Limited | Swindon | 2020 |
| Air Service Technicians Ltd | Perth | 2025 |
| Air Services Limited | Leeds | 1972 |
| Air Services South West Limited | Saltash | 2018 |
| Air Services Tamworth Ltd | Tamworth | 2025 |
| Air Shower Capsules Ltd | London | 2025 |
| Air Solutions (Leeds) Ltd | Baildon | 2009 |
| Air Source Covers Ltd | Leeds | 2022 |
| Air Sourcery Limited | Newport-On-Tay | 2024 |
| Air Spectrum Environmental Limited | Worcester | 1994 |
| Air Spectrum International Limited | Worcester | 2016 |
| Air Sports Promotion Ltd | London | 2016 |
| Air Spray UK Limited | Wombourne | 2017 |
| Air Supply (Lancashire) Limited | Leigh | 2026 |
| Air Supply (Manchester) Limited | Irlam | 2021 |
| Air Supply (North East) Limited | Washington | 2013 |
| Air Supply (Teesside) Limited | Chester Le Street | 2024 |
| Air Support Staff Ltd | Cambridge | 2026 |
| Air Systems Telford Limited | Telford | 1998 |
| Air TEC Holdings Ltd | Northampton | 2009 |
| Air Tech D.S. Limited | Belvedere | 1993 |
| Air Tech Innovations Group Limited | Stoke-On-Trent | 2022 |
| Air Tech Innovations Limited | Stoke-On-Trent | 2016 |
| Air Tech Mechanic Ltd | Cambridge | 2026 |
| Air Tech Support Limited | Stoke-On-Trent | 2023 |
| Air Techniques International Ltd | Letchworth Garden City | 1999 |
| Air Technology and Control Limited | Stoke On Trent | 2001 |
| Air Tools & Compressor Services 2000 Limited | Birmingham | 2008 |
| Air Tools & Compressors Limited | Loughborough | 1984 |
| Air Torque (UK) Limited | Coalville | 2008 |
| Air Tube Repairs & Services Ltd | Bilston | 2023 |
| Air Vehicles Design & Engineering Limited | Isle Of Wight | 1997 |
| Air Vent Tech Ltd | Northampton | 2023 |
| Air Vent Technology Limited | High Wycombe | 1996 |
| Air Viora Ltd | Leicester | 2025 |
| Air Wizard Limited | Ryde | 2014 |
| Air-Demand-Pneumatics Ltd | Bolton | 2025 |
| Air-Fab (Manufacturing) Limited | Hampton Hill | 1993 |
| Air-Line Systems Limited | Ashford | 2003 |
| Air-Log Pneumatic Tube Systems UK Ltd | Ripley | 2024 |
| Air-Sep Ltd | Cambridge | 2023 |
| Air-Switch Limited | Boston | 2021 |
| Air-Tech (Tees Valley) Ltd | | 2001 |
| Air-Water Treatments Limited | Manor Lane Hawarden | 1996 |
| AIR2O Cooling Limited | Bolton | 2014 |
| Aira Gems Ltd | Dudley | 2025 |
| Aira Labs Limited | London | 2024 |
| Airae Ltd | Gloucester | 2025 |
| Airah Bespoke Interiors Ltd | Dewsbury | 2025 |
| Airal Ltd | Glasgow | 2007 |
| Airautomate Ltd | Coleraine | 2023 |
| Airaviontech Ltd | Cambridge | 2025 |
| Airbags International Limited | London | 1985 |
| Airband Technologies Ltd | Cardiff | 2019 |
| Airbase UK Interiors Ltd | Crawley | 2019 |
| Airbench Ltd | Colchester | 1993 |
| Airblade Dynamics Ltd | Penryn | 2017 |
| Airblast Limited | Peterborough | 1986 |
| Airbob Limited | Cowes | 2024 |
| Airbon Home Ltd | London | 2025 |
| Airbond Limited | Newport | 2002 |
| Airborn International Limited | Edenbridge | 1999 |
| Airborn World Ltd | London | 2020 |
| Airborne Avionics Limited | Oswaldkirk | 2006 |
| Airborne Communications Ltd | Fordingbridge | 2013 |
| Airborne Composites Ltd | Lambourn | 1995 |
| Airborne Engineering Limited | Wantage | 2001 |
| Airborne Watches Ltd | Rotherham | 2025 |
| Airbot Co., Ltd | West Midlands, England | 2025 |
| Airbourne Aviation Services Ltd | Stockton-On-Tees | 2024 |
| Airbourne Colours Ltd | Derby | 2010 |
| Airbow Ltd | Cambridge | 2024 |
| Airbox Energy Ltd | London | 2021 |
| Airbus Belfast Limited | Belfast | 2025 |
| Airbus Defence and Space Limited | Hertfordshire | 1989 |
| Airbus Helicopters UK Limited | Oxford | 1974 |
| Airbus Military UK Limited | Carterton | 2012 |
| Airbus Operations Limited | Bristol | 1997 |
| Aircamo Engines Ltd | Deeside | 2020 |
| Aircare Brands Limited | Barnet | 2014 |
| Aircare Compressor Services Limited | Corby | 1991 |
| Aircare Maintenance Limited | Leigh-On-Sea | 2008 |
| Aircare Medical Limited | Bristol | 2013 |
| Aircare Technology Ltd | Hertford | 2015 |
| Aircell Structures Limited | Buckingham | 2005 |
| Airclean Limited | Ashford | 1988 |
| Airco Developments Limited | Edinburgh | 2008 |
| Airco Group Co., Ltd. | London | 2023 |
| Aircomm Maintenance Limited | London | 2002 |
| Aircon Company London Ltd | Wembley | 2021 |