| Alan Roberts Racing Limited | Manufacturing | 2015 |
| Albion Radiology Centre Ltd | Health & social care | 2026 |
| Aldo Limited | Manufacturing | 1986 |
| Alex D Mason PR Limited | Professional & scientific | 2018 |
| Alexanders Sandwiches Ltd | Hospitality | 2014 |
| Aleysa Property Solutions Limited | Real estate | 2020 |
| Aleysa Solutions Limited | Construction | 2019 |
| Alfatech Garage Services Ltd | Wholesale & retail | 2017 |
| Alfatech MOT & Testing Ltd | Wholesale & retail | 2010 |
| Alfred Herbert Limited | Professional & scientific | 2024 |
| ALH Projects Limited | Professional & scientific | 2013 |
| Ali's Kitchen Ltd | Hospitality | 2026 |
| Alice's Kitchen Limited | Wholesale & retail | 2017 |
| Aligned Health & Wellness Limited | Health & social care | 2021 |
| ALL Seasons Gardening Services Ltd | Administrative & support | 2025 |
| Allegro Optical (Marsden) Ltd | Health & social care | 2021 |
| Allegro Optical Limited | Administrative & support | 2016 |
| Allen Windows Ltd | Construction | 2005 |
| Allez Cycling Limited | Extraterritorial | 2014 |
| Alliance Community Home Care Ltd | Health & social care | 2021 |
| Almondbury Garage Huddersfield Limited | Wholesale & retail | 2011 |
| Alpha Auto Concepts Ltd | Manufacturing | 2023 |
| Alpha Construction Management Ltd | Construction | 2019 |
| Alpine Service Station Ltd | Wholesale & retail | 2023 |
| Alta Enterprises Limited | Real estate | 1983 |
| Alternus Ltd | Information & communication | 2021 |
| Alto Comms Limited | Information & communication | 2017 |
| AMB Facility Services Ltd | Administrative & support | 2013 |
| AMB Limited | Wholesale & retail | 2001 |
| Ambas Properties Limited | Real estate | 2022 |
| Ambi Business Solutions Private Limited | Wholesale & retail | 2010 |
| Ambrosius Limited | Extraterritorial | 2010 |
| AMC Electrical Solutions Limited | Construction | 2024 |
| AMC Fire & Smoke Limited | Manufacturing | 2022 |
| AMC Trade Frames Limited | Manufacturing | 2022 |
| Amco Drilling (UK) Limited | Mining & quarrying | 2009 |
| AMI Baxter Limited | Real estate | 2014 |
| AML Cars Limited | Extraterritorial | 2010 |
| Ampl On-Trade Limited | Wholesale & retail | 2003 |
| AN a Word Limited | Administrative & support | 2013 |
| Anderson & Anderson Ltd | Transport & logistics | 2024 |
| Andrew Bottomley Limited | Wholesale & retail | 2018 |
| Andyc Consulting Ltd | Professional & scientific | 2021 |
| Angelo Web Design Limited | Information & communication | 2021 |
| Angels Barber Ltd | Other services | 2025 |
| Angoods 2012 Limited | Transport & logistics | 2012 |
| Anhul Management Limited | Extraterritorial | 2010 |
| Answer AI Ltd | Information & communication | 2023 |
| Antcliff Holdings Ltd | Financial services | 2025 |
| Anthony Dearnley Homes Limited | Construction | 2005 |
| Anthony Lawrence Interiors Ltd | Construction | 2013 |
| Apex Integrity Solutions Ltd | Other services | 2025 |
| Apex Surfacing Ltd | Construction | 2024 |
| Apprentassess Limited | Education | 2024 |
| Aquatec Plumbing & Heating Limited | Construction | 2023 |
| Ara’S Beauty Ltd | Other services | 2025 |
| Arcana Asset Management Ltd | Administrative & support | 2026 |
| Arcanum Group Enterprises Ltd | Households | 2025 |
| Architectural Antiques & Salvage Co Ltd | Other services | 2021 |
| ARK Sustainable Engineering Solutions Ltd | Construction | 2024 |
| Armitage GAS Services (Yorkshire) Ltd | Construction | 2024 |
| Armstrong Holdings Limited | Administrative & support | 2015 |
| ARO Commercial Property Limited | Administrative & support | 2018 |
| Arriole and SON Limited | Other services | 1998 |
| Arrow Rehab Ltd | Administrative & support | 2019 |
| Artisan Hair Academy Ltd | Manufacturing | 2021 |
| Artisan Hair Design Limited | Other services | 2018 |
| Artisan Haircare Collection Limited | Real estate | 2020 |
| Aruba Aquatics Limited | Administrative & support | 2017 |
| ASH Grove IT Consultancy Ltd. | Information & communication | 2016 |
| Ashley Bespoke Properties Ltd | Construction | 2025 |
| Ashley Smith Combustion Limited | Manufacturing | 2003 |
| Ashten & Mason Limited | Wholesale & retail | 2020 |
| Ashton Bennett Ltd. | Other services | 1997 |
| Ashton Foot Clinic Ltd | Other services | 2015 |
| Aside Investment Limited | Administrative & support | 2021 |
| ASK Inc Limited | Wholesale & retail | 2021 |
| Aska Rodgers Limited | Administrative & support | 1961 |
| Aspect Joinery 1994 Ltd | Construction | 2016 |
| Assemble Events Ltd | Professional & scientific | 2019 |
| Assembly Web & Digital Limited | Professional & scientific | 2025 |
| Astbury & White Limited | Health & social care | 2018 |
| Astley Grange Care Home Limited | Health & social care | 2012 |
| Astral Ventures Ltd | Hospitality | 2025 |
| Astute Focus Limited | Professional & scientific | 2012 |
| ASX International Ltd | Financial services | 2022 |
| AT Height Limited | Wholesale & retail | 2019 |
| Atlas Transport Ltd | Transport & logistics | 2016 |
| ATW Living Ltd | Wholesale & retail | 2023 |
| Auhaven Limited | Real estate | 2016 |
| Austonley Developments Limited | Construction | 2000 |
| Auto Electrics Group Limited | Manufacturing | 2016 |
| Autoimotion Limited | Wholesale & retail | 2020 |
| Autonys Garage (Holmfirth) Limited | Wholesale & retail | 2009 |
| AVA Loves Rosie Ltd | Wholesale & retail | 2021 |
| AWG Solutions Ltd | Construction | 2018 |
| B by Button Ltd | Health & social care | 2025 |
| B Medina Newmill Limited | Hospitality | 2023 |
| B. Armitage & SON Limited | Manufacturing | 1968 |
| B.Allsop Limited | Manufacturing | 1964 |