| Alexanders Complete Funeral Services (Holdings) Limited | Financial services | 2019 |
| Alexanders Complete Funeral Services Limited | Other services | 2006 |
| Alexandra Marine & Leisure Ltd | Manufacturing | 2021 |
| Alexandra Quay Developments Ltd | Real estate | 2009 |
| Alexandra Wharf (Grimsby) Residents Company Limited | Households | 2005 |
| Alexatrans Limited | Transport & logistics | 2015 |
| Alfred Bannister Mews (Management) Company Limited | Households | 2009 |
| Alfred Enderby Limited | Manufacturing | 1961 |
| Alfred Terrace Mews (Management) Limited | Households | 2012 |
| Ali's Indian Restaurant (UK) Ltd | Hospitality | 2015 |
| Alira Hospitality Ltd | Wholesale & retail | 2025 |
| Alis Pizza Choice Ltd | Hospitality | 2023 |
| Aliven Limited | Health & social care | 2015 |
| ALL 235 Ltd | Other services | 2024 |
| ALL Good Copy Ltd | Professional & scientific | 2025 |
| ALL Seasons Refrigeration & Air Conditioning Limited | Construction | 2003 |
| ALL Things Good and Nice Community Interest Company | Other services | 2021 |
| Allan Electrical Services (Grimsby) Ltd | Construction | 2010 |
| Allan Henrys Real Estate Limited | Construction | 2025 |
| Allen & Flynn Developments Ltd | Construction | 2021 |
| Allen Wilson Construction Limited | Construction | 1986 |
| Allenby's of Anwick Limited | Manufacturing | 2003 |
| Allied Protek Engineering Solutions Limited | Manufacturing | 2013 |
| Allium Properties Limited | Real estate | 2016 |
| Allmotion Hydraulics Ltd | Professional & scientific | 2022 |
| Allparts-Uk Ltd | Wholesale & retail | 2021 |
| Alltec Electrical Services Limited | Construction | 2018 |
| Alltechnical Ltd | Education | 2025 |
| Almasan Transport Ltd | Transport & logistics | 2025 |
| Almial Ltd | Transport & logistics | 2021 |
| ALMS4U Ltd | Construction | 2010 |
| Alneeq Ltd | Wholesale & retail | 2015 |
| Aloe (Liincolnshire) Limited | Extraterritorial | 2025 |
| Alpha Assetable Ltd | Financial services | 2024 |
| Alpha IWM Ltd | Real estate | 2018 |
| Alpha X Industrial Service Limited | Professional & scientific | 2019 |
| Alta Studio Ltd | Professional & scientific | 2017 |
| Altar Logistics Ltd | Transport & logistics | 2014 |
| Altro Drinks Ltd | Wholesale & retail | 2024 |
| Alver Estates Ltd | Real estate | 2019 |
| Alyx Aviation Logistics Ltd | Administrative & support | 2025 |
| AM2025 Limited | Health & social care | 2025 |
| Amadeo Engineering Construction Ltd | Professional & scientific | 2020 |
| Amadeo Group Ltd | Financial services | 2026 |
| Amadeo Property Ltd | Construction | 2025 |
| Amaradia Limited | Professional & scientific | 2013 |
| Amazing Glazing Limited | Wholesale & retail | 1987 |
| Amazon Refrigeration Limited | Other services | 2011 |
| Amber Connections Limited | Real estate | 2024 |
| Amberdora Limited | Real estate | 2006 |
| Ambleside Inns Limited | Hospitality | 2014 |
| American Machine (Europe) Ltd | Wholesale & retail | 2025 |
| Amersham Studios Limited | Professional & scientific | 2014 |
| AMF Lifting Ltd | Construction | 2021 |
| Amft Services Ltd | Extraterritorial | 2024 |
| AMI Cosmetics Limited | Health & social care | 2009 |
| Amik (Stallingborough) Ltd | Real estate | 2026 |
| Amira Transport Ltd | Transport & logistics | 2021 |
| Amon Seafoods Limited | Wholesale & retail | 2024 |
| AMP Lifting & Plant Services Limited | Construction | 2024 |
| Ampbuildgrimsby Limited | Construction | 2025 |
| AMR P & P Ltd | Manufacturing | 2013 |
| AMY Broughton Aesthetics Ltd | Other services | 2021 |
| Amycheks Ltd | Professional & scientific | 2025 |
| AMZ84 Ltd | Transport & logistics | 2024 |
| Analytica Inspection Limited | Professional & scientific | 2019 |
| Anastamosis Limited | Health & social care | 2018 |
| Ancs Investments Limited | Extraterritorial | 2024 |
| Anderby Driving Centre Limited | Education | 2002 |
| Anderlea Butters Marketing Consultancy Limited | Professional & scientific | 2023 |
| Anderson Capital Investments Limited | Financial services | 2023 |
| Anderson Capital Limited | Financial services | 2018 |
| Anderson Capital Real Estate Limited | Real estate | 2023 |
| Anderson Eastgate Limited | Real estate | 2026 |
| Anderson Hall Investments Limited | Professional & scientific | 2025 |
| Andrei&Madalin ZAR Limited | Transport & logistics | 2023 |
| Andrew Brewster Consultancy Ltd | Other services | 2023 |
| Andrew Browning Transport Limited | Transport & logistics | 2012 |
| Andrew Couriers Limited | Transport & logistics | 2018 |
| Andrew Dulieu Limited | Financial services | 2015 |
| Andrew Telfer Limited | Information & communication | 2013 |
| Andrew Walker Services Limited | Construction | 2023 |
| Andy Build Ltd | Construction | 2018 |
| Andy Winter Plastering Limited | Construction | 2011 |
| Andy's Seafoods (Grimsby) Limited | Hospitality | 1998 |
| Anemoi Techs Limited | Professional & scientific | 2022 |
| Angel Touch Care Ltd | Health & social care | 2026 |
| Angela Yates Food Systems Compliance Ltd | Professional & scientific | 2022 |
| Angela's Cutting Crew Limited | Other services | 2015 |
| Angelic Care LLP | | 2019 |
| Angelin Trans Ltd | Transport & logistics | 2025 |
| Angle for the Community C.I.C. | Arts & recreation | 2022 |
| Anglo American Lightning Organisation Limited | Arts & recreation | 1999 |
| Anglo Arabian Lightning Organisation Ltd | Manufacturing | 2023 |
| Anipay Ltd | Extraterritorial | 2012 |
| Anita Grove Limited | Real estate | 2019 |
| Anlui Bar Limited | Hospitality | 2019 |
| Annapurna Homes Ltd | Real estate | 2025 |
| Anne-T-Dote Limited | Health & social care | 2016 |
| ANP Geotechnics Ltd | Construction | 2024 |