| Astraprint UK Ltd | Birmingham | 2025 |
| Astrastone Worktops Ltd | London | 2025 |
| Astratec Electronics Limited | | 1981 |
| Astratelli Limited | Pulborough | 2013 |
| Astratium Ltd | Stratford-Upon-Avon | 2022 |
| Astratus Limited | Reading | 2024 |
| Astravar Ltd | London | 2025 |
| Astrazeneca PLC | Cambridge | 1992 |
| Astrea Energies Europe Ltd | Guildford | 2023 |
| Astreea (UK) Ltd | London | 2020 |
| Astrelise Ltd | Brough | 2026 |
| Astrex Motors Ltd | London | 2025 |
| Astric Medical Limited | Worthing | 2010 |
| Astrion Informatics Ltd | Cambridge | 2025 |
| Astrix Golf Limited | Barnsley | 2024 |
| Astro Antenna Limited | Stockport | 2014 |
| Astro Autocare Ltd | Bradford | 2025 |
| Astro CBD Club Ltd | Northampton | 2019 |
| Astro Creations Ltd | Fareham | 2024 |
| Astro Engineering Limited | Waterlooville | 2024 |
| Astro Events Ltd | Manningtree | 2010 |
| Astro Fabrications Ltd | Sunderland | 2020 |
| Astro Hydration Limited | Sidcup | 2025 |
| Astro Lighting (China) Limited | Harlow | 2015 |
| Astro Lighting (Europe) Limited | Harlow | 2015 |
| Astro Print Limited | Gosforth | 1983 |
| Astro Safety Solutions Ltd | Chatham | 2017 |
| Astro Tuff Truk Ltd | Ryehill | 2022 |
| Astro's Pizza Company Limited | Edinburgh | 2025 |
| Astroe Limited | Leamington Spa | 2014 |
| Astrofarhi Technik Ltd | Cambridge | 2024 |
| Astroflame (Fireseals) Limited | Winchester | 1994 |
| Astromel Ltd | London | 2023 |
| Astromezz Limited | Gloucester | 1997 |
| Astron Packaging Limited | Manchester | 1996 |
| Astron Systems Ltd | Macclesfield | 2021 |
| Astropack Gulf Ltd | Welling | 2025 |
| Astrophysics UK Limited | London | 2020 |
| Astropol Limited | Hindley Green Wigan | 1994 |
| Astroscent Ltd | Wiveliscombe | 2019 |
| Astrosyn International Technology Limited | Chatham | 1974 |
| Astrotanks Ltd | Whitchurch | 2017 |
| Astrotrac Limited | Bristol | 2006 |
| Astrum Pharma Ltd | London | 2023 |
| Asturfeito UK Ltd | London | 2022 |
| Astute (Scotland) Limited | Forfar | 2003 |
| Astute Carpentry & Construction Ltd | Southampton | 2023 |
| Astute Devices Limited | Cambridge | 2026 |
| Astute Lifts Limited | Otford | 2008 |
| Astute Lighting Ltd | Blackburn | 2011 |
| Astute Music Limited | Cheshire | 2003 |
| Astwell Augers Limited | Kettering | 1982 |
| Astwood CAD Ltd | Cheltenham | 2015 |
| Astéri Stat Track Limited | Wymondham | 2025 |
| ASU Enterprises Ltd | London | 2022 |
| Asua Ellimah London Ltd | London | 2022 |
| Asul Import and Export Co., Ltd | West Midlands, England | 2024 |
| Asulkowski Ltd | Greenford | 2014 |
| Asuna Ltd | Birmingham | 2026 |
| Asvo Health Technologies Limited | London | 2018 |
| ASW Electrical & Engineering Ltd | Wilmslow | 2025 |
| ASW Sheerness Steel Limited | Cardiff | 1966 |
| ASW Signalling Limited | Gillingham | 2014 |
| ASW Welding & Construction Services Ltd | Walsall | 2020 |
| Aswaar Almadina Development Services Ltd | Cardiff | 2025 |
| Aswak Wibkhaliji Ltd | London | 2025 |
| Aswat Leathers Limited | London | 2015 |
| Aswat-Raja Enterprise Limited | London | 2013 |
| Aswin Chicken Ltd | Colindale | 2017 |
| ASY Maintenance Services Ltd | Chester Le Street | 2022 |
| ASY Products Limited | Bradford | 2023 |
| Asya Commercial Kitchen Ltd | Liverpool | 2024 |
| ASYA23 Ltd | Morden | 2025 |
| Asyad Trading Ltd | London | 2024 |
| Asygames Ltd | Derby | 2024 |
| Asylum Coffee Limited | Swindon | 2024 |
| Asymchem Limited | Sandwich | 2017 |
| Asymetric Limited | London | 2017 |
| Asymmetrical Advantage Ltd | Bexleyheath | 2023 |
| Asynt Limited | Ely | 2004 |
| ASZ FIX Building Ltd | Burnham-On-Crouch | 2024 |
| ASZ Food Ltd | Leicester | 2023 |
| AT & GD Commercial Services Ltd | Borehamwood | 2018 |
| AT & NT Limited | Beckenham | 2012 |
| AT & Sons Services and Logistics Ltd | Bolton | 2024 |
| AT 36 Middle Street Ltd | Brixham | 2025 |
| AT 3D-SQUARED Ltd | Grange-Over-Sands | 2007 |
| AT Bespoke Carpentry & Joinery Limited | Thatcham | 2018 |
| AT Carpentry & Cabinetry Limited | Aylesbury | 2020 |
| AT Carpentry Solutions Ltd | Ilford | 2026 |
| AT Commercial Vehicle Services Ltd | London | 2015 |
| AT Design & Creative Ltd | Tadworth | 2018 |
| AT Engine Controls Limited | Worsley | 2004 |
| AT Engineering Services Ltd | Saltburn-By-The-Sea | 2012 |
| AT Engineering Technology Ltd | Tadley | 2016 |
| AT Event MCR Ltd | Manchester | 2023 |
| AT Hampson Services Ltd | Leicester | 2024 |
| AT Home With Ruth Limited | Chorley | 2017 |
| AT Kinetics Limited | Cheshire | 2003 |
| AT Last Events Limited | Brentwood | 2018 |