| Aiolec Ltd | London | 2024 |
| Aion Dental Designs Ltd | London | 2021 |
| Aion Engineering Limited | Greater Manchester | 2016 |
| Aion Voice Ltd | London | 2024 |
| Aione Ltd | London | 2023 |
| Aioro Limited | London | 2018 |
| Aiotomate Ltd | London | 2025 |
| Aipco Limited | Harrow | 2024 |
| Aipex Robotics Limited | Durham | 2025 |
| Aiproducts Sports UK Ltd | Peterborough | 2021 |
| Air & Bond Ltd | London | 2021 |
| Air & Liquid Filtration Limited | Rowley Regis Warley | 1956 |
| Air & Power Services Ltd | Poole | 2002 |
| Air & Water Projects Ltd | Romford | 2014 |
| Air 2 GAS Tech Ltd | London | 2020 |
| Air and Fire Compliance Limited | Liverpool | 2010 |
| Air and Fire Services Limited | Liverpool | 2018 |
| Air Anglia Aerospace Limited | Norwich | 2006 |
| Air Audio Services Limited | Henley-On-Thames | 2015 |
| Air Bearings Limited | Ferndown | 1993 |
| Air Bike Forks Limited | Basingstoke | 2020 |
| Air Care Products Limited | Essex | 1991 |
| Air Cargo Services Limited | Hayes | 2007 |
| Air Carpentry Ltd | St. Austell | 2026 |
| Air Cocoon Limited | London | 2011 |
| Air Compressor Distribution Limited | Bristol | 2011 |
| Air Compressor Engineering Ltd | Harlow | 2009 |
| Air Compressor Maintenance Ltd | Alfreton | 2021 |
| Air Compressor Management Ltd. | Cannock | 2009 |
| Air Compressor Services (Worcs) Limited | Bromsgrove | 2016 |
| Air Compressors and Components Limited | Liverpool | 2024 |
| Air Compressors Direct Limited | Dunstable | 2015 |
| Air Compressors North East Limited | Durham City | 2025 |
| Air Concept Refrigeration Limited | Newbury | 2014 |
| Air Conditioning and Heating 4 U Limited | Dudley | 2011 |
| Air Conditioning Energy Solutions Ltd | Hollinwood | 2015 |
| Air Conditioning Sales UK Limited | Shotts | 2001 |
| Air Conditioning Service London Ltd | London | 2019 |
| Air Conditioning Work Limited | Bordon | 2014 |
| Air Consultants (Leeds) Ltd | Leeds | 2024 |
| Air Control Entech Limited | Aberdeen | 2016 |
| Air Control Industries Limited | Axminster | 1969 |
| Air Control Ventilation Limited | Caerphilly | 2013 |
| Air Controls and Compressors Ltd | Liverpool | 1982 |
| Air Cooled Environments Limited | Brandon | 2013 |
| Air Corp Global Limited | Cottingham | 2023 |
| Air Covers Limited | Wrexham | 2006 |
| Air Direct Ltd | Prestonpans | 2021 |
| Air Distribution Solutions Ltd | Hull | 2019 |
| Air Domestique Limited | Maldon | 1981 |
| Air Door Services Limited | Wolverhampton | 2004 |
| Air Dryer Technology Limited | Salford | 2005 |
| Air Eco Ltd | St. Leonards-On-Sea | 2023 |
| Air END Repair Limited | Birmingham | 2011 |
| Air Engineering Group Ltd | Forest Row | 2000 |
| Air Engineering Ltd | Oldham | 2009 |
| Air Engineering Services Ltd | Oldham | 2020 |
| Air EO Ltd | Durham | 2018 |
| Air Filters Limited | Cramlington | 1998 |
| Air Filtration Solutions Limited | Morecambe | 2025 |
| Air Flow Comfort Manufacturing Ltd | Hereford | 2022 |
| Air Flow Compressor Services Limited | Wakefield | 2011 |
| Air for Life UK Ltd | Milton Keynes | 2017 |
| Air Free Solutions Ltd | London | 2025 |
| Air Fresh Services Limited | Exeter | 2014 |
| Air Handlers (Northern) Limited | Salford | 1992 |
| Air Handling Components Limited | Salford | 1998 |
| Air Handling Equipment Limited | Merseyside | 1979 |
| Air Handling Systems Limited | County Durham | 2000 |
| Air Hunter Ltd | Cambridge | 2026 |
| Air Industrial Company Ltd. | Waltham Abbey | 1989 |
| Air Industrial Developments Limited | West Bromwich | 1998 |
| Air Innovation Robotics Limited | Edinburgh | 2024 |
| Air Knife Systems Limited | Northampton | 2019 |
| Air Lines & Compressors (Yorks) Limited | North Humberside | 2003 |
| Air Liquide Limited | Birmingham | 1987 |
| Air Liquide OIL and GAS Services Limited | Birmingham | 2013 |
| Air Liquide UK Limited | Birmingham | 1928 |
| Air Management & Design Ltd | Manchester | 1998 |
| Air Management Systems Limited | London | 1994 |
| Air Matters Ltd | London | 2018 |
| Air Metrics Limited | Toddington | 2026 |
| Air Movement & Fabrications Ltd | Nottingham | 2013 |
| Air Naturals Ltd | Ardrossan | 2025 |
| Air Next Ltd | Cambridge | 2023 |
| Air Note International Ltd | Chelmsford | 2024 |
| Air Oprea SRV Limited | Bristol | 2025 |
| Air Paint Finish Ltd | Bromley | 2025 |
| Air Pillows Limited | Aylesbury | 2009 |
| Air Plants Dust Extraction Limited | Leicester | 1996 |
| Air Plasma Limited | Loughborough | 2010 |
| Air Power Aerospace Technologies Limited | Derby | 2003 |
| Air Power East Limited | Bury St Edmunds | 1991 |
| Air Power Group Ltd | Chessington | 2025 |
| Air Power Products Limited | Dinnington Sheffield | 1989 |
| Air Power Solutions Ltd | Chessington | 2023 |
| Air Pressure Solutions Ltd | Sevenoaks | 2013 |
| Air Products (BR) Limited | Chertsey | 1990 |
| Air Products Equipment Limited | Chertsey | 2020 |
| Air Products Llanwern Limited | Chertsey | 1974 |