| Air Force Renewables Ltd | Doncaster | 2025 |
| Air Global Integrated Solutions Ltd | Addlestone | 2021 |
| Air Heat Services UK Ltd | Redditch | 2026 |
| Air Host Flex Ltd | London | 2018 |
| Air Hvac Ltd | Sunbury-On-Thames | 2024 |
| Air Improve Limited | Winchester | 1998 |
| Air Intelligence Ltd | Maidenhead | 2012 |
| Air Jointing Limited | Mountain Ash | 2026 |
| Air King Solutions Ltd | Galashiels | 2025 |
| Air Link Group Limited | Birmingham | 2005 |
| Air LUX Limited | Burnham-On-Crouch | 2007 |
| Air Management Solutions Limited | Bovey Tracey | 2002 |
| Air Metal Ltd | London | 2018 |
| Air Movement Design (Northern) Limited | Halifax | 2007 |
| Air Movement Technology Ltd | Sheffield | 2023 |
| Air OFF Solutions Ltd | London | 2025 |
| Air on Group Ltd | London | 2022 |
| Air Performance Scotland Ltd | Glasgow | 2026 |
| Air Planet Ltd | Buckhurst Hill | 2018 |
| Air Plumbing & Heating Ltd | Burgess Hill | 2018 |
| Air Plus (UK) Limited | Basildon | 2013 |
| Air Pressure Test UK Ltd | Northampton | 2008 |
| Air Pressure Testing Scotland Ltd | Biggar | 2017 |
| Air Projects Limited | Witham | 2008 |
| Air Property Services Ltd | Stonehouse | 2018 |
| Air Quality Services Ltd | High Wycombe | 1991 |
| Air Quality Testing Limited | Carmarthen | 2017 |
| Air Quality Testing Solutions Limited | Carmarthen | 2022 |
| Air Quantum Ltd | London | 2014 |
| Air RO Construction Ltd | Peterborough | 2018 |
| Air Roofing Limited | Sutton Coldfield | 2014 |
| Air Rush Ltd | Northampton | 2019 |
| Air Scaffolding Limited | Redditch | 1996 |
| Air Scaffolding Solutions Ltd | Cheltenham | 2025 |
| Air Seal Glazing Limited | Slough | 2010 |
| Air Services & Systems (Europe) Limited | Manchester | 2001 |
| Air SIX Limited | London | 2022 |
| Air Snowdonia Limited | Liverpool | 2022 |
| Air Source Cambridge Limited | Cambridge | 2023 |
| Air Source Energy Ltd | Wirral | 2019 |
| Air Source Energy South Wales Limited | Swansea | 2022 |
| Air Source Heat Pump (Ashp) Ltd | London | 2020 |
| Air Source Heating & Cooling Ltd | Ashford | 2024 |
| Air Source Heating and Servicing Ltd | Sheffield | 2023 |
| Air Source Heating Pump Ltd | London | 2022 |
| Air Source Installations Limited | Grays | 2024 |
| Air Source One Limited | Bellshill | 2010 |
| Air Source South West Ltd | Bodmin | 2019 |
| Air Sourced Ltd | Carlisle | 2022 |
| Air Stream 65 Ltd | Crosby | 2025 |
| Air Supply (Windsor) Limited | Ascot | 2007 |
| Air Systems (SW) Limited | Bristol | 2001 |
| Air Systems Kent Ltd | West Malling | 2013 |
| Air Tech AC Systems Ltd | Belvedere | 2017 |
| Air Technical Services Limited | Great Chesterford | 2002 |
| Air Technique Filtration Limited | Stockport | 2016 |
| Air Technology Products Ltd | London | 2021 |
| Air Technology Systems Limited | Bromsgrove | 1992 |
| Air TEK Installations Limited | Hockley | 2016 |
| Air Temp Solutions (NW) Limited | Handforth | 2020 |
| Air Temp Solutions Limited | Hull | 2015 |
| Air Test East Anglia Limited | Wisbech | 2022 |
| Air Test Services Ltd | London | 2026 |
| Air Testing Limited | Great Chesterford | 2008 |
| Air Tight Mechanical Services Ltd | Steyning | 2022 |
| Air Tight Roofing and Cladding Limited | Stoke-On-Trent | 2015 |
| Air Tight Ventilation Limited | Welling | 2018 |
| Air Tightness and Building Energy Consultants Ltd. | Enniskillen | 2010 |
| Air Tightness Assessors Limited | Essex | 2006 |
| Air Tightness Solutions Limited | Wantage | 2012 |
| Air Tightness Testing Scotland Limited | Strathaven | 2012 |
| Air to Air Heat Pump Ltd | London | 2020 |
| Air to Water Heat Pumps Ltd | London | 2020 |
| Air Transfer Systems Ltd | Nottingham | 2007 |
| Air Utilities Limited | Stockport | 2020 |
| Air Vent Quality Ltd | Birmingham | 2019 |
| Air Vent Services Ltd | Plymouth | 2018 |
| Air Ventilation Solution & Services Limited | London | 2020 |
| Air Waze UK Ltd | Doncaster | 2023 |
| Air WE Go Ltd | Loughton | 2023 |
| Air X Acoustics Ltd | Cressex Business Park | 2021 |
| Air X Developments Ltd | High Wycombe | 2022 |
| Air Xtreme Limited | Bristol | 2008 |
| Air-Change Ventilation Limited | Chesterfield | 2001 |
| Air-Con Electro Engineering Ltd | Hayes | 2026 |
| Air-Con on Demand Ltd | Bishop'S Stortford | 2025 |
| Air-Conditioning Control Limited | Halstead | 2023 |
| Air-Modification Limited | Farnborough | 2013 |
| Air-Qual Limited | Bolton | 2006 |
| Air-Site Ltd | Poole | 2006 |
| Air-Tech Engineering Ltd | Aberdeen | 2021 |
| Air/Con Jimbalt (Mechanical) Ltd | London | 2021 |
| AIR2AIR Air Conditioning Ltd | High Peak | 2005 |
| AIR2CAMBRIDGE Ltd | Solihull | 2022 |
| AIR2ELECTRICAL Ltd | Solihull | 2022 |
| AIR2HEAT Ltd | Oswestry | 2020 |
| AIR2NRG Limited | Cranbrook | 2009 |
| Aira Home UK Ltd | Stretford | 2022 |
| Aira Property Services Limited | Croydon | 2023 |
| Airah Designs Limited | Manchester | 2020 |