| Aspen Bathrooms Limited | Construction | 2014 |
| Aspen Park Management Company (Barnoldby-Le-Beck) Limited | Households | 2021 |
| Aspen Properties (Waltham) Limited | Real estate | 2023 |
| Aspenvail Business Systems (UK) Limited | Information & communication | 1990 |
| Aspin Digital TV Solutions Ltd | Information & communication | 2012 |
| Aspire CL Ltd | Other services | 2007 |
| Aspire Residential Properties Ltd | Real estate | 2025 |
| Asquith Specialist Plant Limited | Construction | 2004 |
| ASR UK Group Ltd | Real estate | 2025 |
| Asset Angel Ltd | Professional & scientific | 2007 |
| Assist Health & Safety Limited | Other services | 2010 |
| Association of Professional Virtual Assistants Limited | Other services | 2020 |
| Assuncao and Sons Logistics Limited | Transport & logistics | 2018 |
| Assured Health Limited | Financial services | 2003 |
| Astec INT (Nanotech) Ltd | Other services | 2013 |
| Astech Developments Ltd | Professional & scientific | 1997 |
| Astectherm International Ltd | Financial services | 2017 |
| Astrakhan Ltd | Professional & scientific | 2025 |
| Asturiasbathrooms.Co.Uk Limited | Wholesale & retail | 2013 |
| AT Auto (Grimsby) Limited | Wholesale & retail | 2003 |
| AT Inspections Ltd | Professional & scientific | 2026 |
| AT MOT Ltd | Wholesale & retail | 2015 |
| ATG Building Ltd | Construction | 2023 |
| Athene Advisory Ltd | Professional & scientific | 2006 |
| Athenium Systems Ltd | Information & communication | 2026 |
| Atholl Health Ltd | Health & social care | 2015 |
| Athom Inspection Limited | Construction | 2014 |
| Atkinson's Joinery Limited | Construction | 2017 |
| Atlanta Rose Limited | Wholesale & retail | 2006 |
| Atlantic Beauty Parlour Ltd | Other services | 2022 |
| Atlantic Blue Seafoods Limited | Manufacturing | 2014 |
| Atlantic Fresh Limited | Wholesale & retail | 2005 |
| Atlantic Ocean Seafood Limited | Wholesale & retail | 2008 |
| Atlantis Imagery Limited | Information & communication | 2015 |
| Atlantis Soft Play Limited | Arts & recreation | 2019 |
| Atlantis Technical Resources Limited | Construction | 2018 |
| Atlas Decoration & Renovation Ltd | Construction | 2020 |
| Atlas House Living Ltd | Construction | 2025 |
| Atlas Technical Solutions Ltd. | Construction | 2017 |
| Atmosfear Costume & Production Limited | Manufacturing | 2008 |
| Atoz Fire Limited | Professional & scientific | 2013 |
| Attainable Limited | Information & communication | 2010 |
| Attainment Training Ltd | Administrative & support | 2010 |
| Atwill Associates Limited | Professional & scientific | 2014 |
| Audi Volkswagen Centre Ltd | Wholesale & retail | 2025 |
| Audiovox Publishing Ltd | Manufacturing | 2025 |
| Aurora Rock Limited | Wholesale & retail | 2022 |
| Aurora Shore Ltd | Real estate | 2023 |
| Austin's Autos Grimsby Ltd | Wholesale & retail | 2019 |
| Auto Parts Vault Ltd | Wholesale & retail | 2024 |
| Auto Services (Grimsby) Limited | Wholesale & retail | 2013 |
| Automotive Hub Ltd | Professional & scientific | 2020 |
| Autoreg Limited | Manufacturing | 2002 |
| Auxilium Ventures Limited | Professional & scientific | 2019 |
| AVA & Jack Limited | Professional & scientific | 2018 |
| Avanos Foods Ltd | Hospitality | 2026 |
| Avant Partnership Limited | Education | 2007 |
| Avant Skills Academy Limited | Extraterritorial | 2019 |
| Avant Solutions Limited | Real estate | 2017 |
| Avantriq Limited | Professional & scientific | 2019 |
| Avatar IP Law Limited | Professional & scientific | 2025 |
| Aveiro School of Karate Ltd | Education | 2024 |
| Aventis Property Services Limited | Construction | 2026 |
| Avenue Lets Limited | Real estate | 2016 |
| Avenue Realtors Ltd | Real estate | 2024 |
| Aviation Multi Services Limited | Transport & logistics | 2015 |
| Avro Contracts Ltd | Administrative & support | 2017 |
| AW Quality Management Limited | Construction | 2020 |
| AW Renovation Solution Ltd | Construction | 2024 |
| Awat Bokani Ltd | Wholesale & retail | 2026 |
| Axholme Engineering Limited | Professional & scientific | 2018 |
| Axis Fabrications Limited | Manufacturing | 2026 |
| Axis Property Group Ltd | Real estate | 2019 |
| Axons Consultancy Ltd | Information & communication | 2021 |
| Ayas Style Ltd | Other services | 2022 |
| Ayla Financial Management Limited | Professional & scientific | 2026 |
| Ayona Aesthetics Limited | Health & social care | 2025 |
| Ayre Electrical Ltd | Construction | 2025 |
| Ayyan Trading Ltd | Wholesale & retail | 2025 |
| AZ Lighting Trading AS the Lightshop Ltd | Wholesale & retail | 2019 |
| Azikal Metal Limited | Manufacturing | 2025 |
| Azzaengineering Ltd | Professional & scientific | 2024 |
| B & B Services (Grimsby) Limited | Health & social care | 2019 |
| B C Engineering & Construction Ltd | Construction | 2023 |
| B G Bait Limited | Wholesale & retail | 2016 |
| B Marsh Decorators Ltd | Construction | 2013 |
| B Plant Lincs Ltd | Construction | 2021 |
| B S B (Lincs.) Trading Ltd. | Construction | 2014 |
| B&B Waste and Garden Services Ltd | Water & waste | 2025 |
| B&D Trans Ltd | Transport & logistics | 2019 |
| B&H Commerce Ltd | Wholesale & retail | 2025 |
| B&M Investments Group Limited | Professional & scientific | 2020 |
| B&O Ventures Limited | Construction | 2018 |
| B-G Medical Limited | Administrative & support | 2017 |
| B.J.B. Lift Trucks Limited | Wholesale & retail | 1991 |
| B.Unleashed Ltd | Professional & scientific | 2022 |
| Baboli Ltd | Real estate | 2025 |
| Back 2 Health Chiropractic Limited | Health & social care | 2007 |
| Badger Close (Humberston) Limited | Real estate | 2024 |
| Badger Site Services Limited | Construction | 2024 |