| Ainprivate Limited | Ilkeston | 2025 |
| Ainsbury Ltd | London | 2025 |
| Ainscope Ltd | Leeds | 2025 |
| Ainscott Online Ltd | Manchester | 2024 |
| Ainscough Atkinson & Co Limited | Wigan | 2026 |
| Ainscough Contemporary Art Limited | Aveton Gifford | 1995 |
| Ainscough Motor Group Ltd | Bolton | 2016 |
| Ainsdale Car Centre Ltd | Southport | 2014 |
| Ainsdale Eltham Ltd | Leicester | 2025 |
| Ainsdale Garage Limited | Burscough | 2006 |
| Ainsdale Home&Garden Ltd | Southport | 2024 |
| Ainsdale Store Ltd | Ainsdale | 2025 |
| Ainsheen Limited | Burgess Hill | 2021 |
| Ainslee Ltd | Bristol | 2020 |
| Ainsley and Brown Carpets Ltd | Morden | 2023 |
| Ainsley Autos Ltd | Birmingham | 2023 |
| Ainsley Wilmot Ltd | London | 2014 |
| Ainslie Automotive Ltd | Plymouth | 2025 |
| Ainsliem Ltd | Darlington | 2024 |
| Ainsly Limited | Cheltenham | 2017 |
| Ainstrading UK Ltd | Slough | 2018 |
| Ainsworth Auto Electrical Limited | London | 2002 |
| Ainsworth Clothing Company Ltd | Bolton | 2019 |
| Ainsworth Country Ltd | Birmingham | 2020 |
| Ainsworth News Ltd | Whalley | 2003 |
| Ainsworth Road Butchers Ltd | Bury | 2019 |
| Ainsworth Surgical Supplies Limited | Manchester | 2010 |
| Ainsworths Garage Limited | Ulverston | 2016 |
| Aint Ltd | London | 2022 |
| Aintaz Ltd | Ilford | 2025 |
| Aintree Auto Center Limited | Liverpool | 2026 |
| Aintree Auto Tyres Ltd | Liverpool | 2026 |
| Aintree Cake Limited | Aintree | 1988 |
| Aintree Caravan Services Ltd | Liverpool | 2014 |
| Aintree Clutch & Gearboxes Ltd | Bootle | 2026 |
| Aintree Furniture Ltd | Ilford | 2023 |
| Aintree Garages Ltd | Blackpool | 2008 |
| Aintree Interiors Limited | Liverpool | 2017 |
| Aintree Motors Limited | Liverpool | 2006 |
| Aintree Service Centre Ltd | Liverpool | 2008 |
| Aintree Sofa's Limited | Liverpool | 2015 |
| Aintree Trade Ltd | Liverpool | 2025 |
| Ainuso Limited | Cardiff | 2025 |
| Ainz Global Ltd | Manchester | 2025 |
| Ainz Trading Ltd | Leicester | 2019 |
| AIO Clothing and Retail Ltd | London | 2025 |
| AIO Prime Ltd | London | 2026 |
| AIO Security Ltd | London | 2024 |
| AIO Tech Solutions Ltd | Bolton | 2024 |
| Aiodistribution Ltd | London | 2007 |
| Aioes (ALL in One Energy Solutions) Ltd | Edinburgh | 2024 |
| Aiol International Solutions Ltd | London | 2023 |
| Aiology Limited | Walsall | 2023 |
| Aioma Limited | Milton Keynes | 2025 |
| Aion Auto UK Limited | London | 2025 |
| Aion Ecom Ltd | London | 2019 |
| Aion Enterprises Ltd | Liverpool | 2024 |
| Aion Kubera Limited | London | 2022 |
| Aion Think Ltd | London | 2025 |
| Aione Elec Technology Limited | London | 2021 |
| Aionios Group Services Limited | Mildenhall | 2016 |
| Aionstor Ltd | Tadworth | 2025 |
| AIP Group Ltd | Hayes | 2026 |
| AIP Welding Supplies Limited | Bridgwater | 2015 |
| Aipad Limited | Stroud | 2024 |
| Aipairs Ltd | Bristol | 2025 |
| Aipc Holdings Ltd | Harrogate | 2023 |
| Aiphone UK Limited | London | 2015 |
| Aiping Ltd | London | 2025 |
| Aiple Limited | Canterbury | 2025 |
| AIQ Enterprise Limited | Birmingham | 2025 |
| AIQ Global Ltd | Bolton | 2024 |
| Aiqahs Boutique Ltd | Bradford | 2018 |
| Aiqahs Boutique Nelson Ltd | Bradford | 2017 |
| Aiqahs Bridal Ltd | Bradford | 2021 |
| Aiqahs Limited | Bradford | 2024 |
| Aiqtech Ltd | London | 2025 |
| Air & Marine Products Ltd | Reading | 2013 |
| Air & More Limited | Richmond | 2015 |
| Air Accessories (Sheffield) Limited | Sheffield | 1974 |
| Air Ambulance Promotions Limited | Chatham | 1991 |
| Air Art Ltd | St. Albans | 2026 |
| Air Audio Visual Limited | Ascot | 2008 |
| Air Auto ID Resource Limited | Leicester | 2003 |
| Air Balloon Pharma Limited | London | 2025 |
| Air Blast Products Limited | Ka6 6Lf | 2025 |
| Air Bloom Balloons Ltd | London | 2023 |
| Air Box Global Ltd | London | 2023 |
| Air BP Limited | Middlesex | 1973 |
| Air Brake One Ltd | Wolverhampton | 2026 |
| Air Business Consultants Holding Ltd | New Malden | 2019 |
| Air Card Trading Co., Ltd | Kington | 2023 |
| Air Care Compressors Limited | Cannock | 1999 |
| Air Care Solutions Limited | Cheadle | 2020 |
| Air Cat Limited | Sheffield | 1991 |
| Air Commercial Services Ltd. | Ballymena | 2013 |
| Air Compensation Ltd | Cardiff | 2025 |
| Air Conditioning Accessories (North West) Limited | Harrogate | 2006 |
| Air Conditioning Accessories Limited | Harrogate | 2004 |
| Air Conditioning and Refrigeration Supplies Limited | Bewdley | 2022 |