| AI Mortgages Ltd | Real estate | 2018 |
| AI Smart Tech Ltd | Wholesale & retail | 2023 |
| Aigineer Ltd | Professional & scientific | 2024 |
| Aimee's Corner Cafe Limited | Hospitality | 2024 |
| Aina Financial Services Limited | Professional & scientific | 2018 |
| Ainthorpe Property Services Limited | Construction | 2025 |
| Air Distribution Solutions Ltd | Manufacturing | 2019 |
| Air Temp Holdings Limited | Financial services | 2020 |
| Air Temp Solutions Limited | Construction | 2015 |
| Airco (Yorkshire) Limited | Construction | 2002 |
| Airco Centre of Excellence Limited | Education | 2016 |
| Airco Limited | Extraterritorial | 2021 |
| Airco Property Holdings Limited | Extraterritorial | 1997 |
| Airco Refrigeration and Airconditioning Limited | Construction | 1997 |
| Aircon 365 Limited | Construction | 2010 |
| Aircraft Production Maintenance Services Ltd | Manufacturing | 2012 |
| Airfuss Limited | Information & communication | 2024 |
| Airgun Hunting Solutions Ltd | Arts & recreation | 2015 |
| Airkool Contracts Limited | Construction | 1998 |
| Airkool Holdings Limited | Professional & scientific | 1992 |
| Airkool Projects Limited | Construction | 2008 |
| Airmed Psychology Limited | Professional & scientific | 2021 |
| Airsa Solutions Ltd | Information & communication | 2026 |
| Airsoft & Military Simulations Ltd | Wholesale & retail | 2021 |
| Airtime Escapes Limited | Administrative & support | 2024 |
| Airtinary Ltd | Administrative & support | 2026 |
| Airweb Urbanthings Limited | Financial services | 2022 |
| Aitm Systems Ltd | Information & communication | 2024 |
| Aitransform Academy Ltd | Information & communication | 2026 |
| Aivilo Properties Ltd | Real estate | 2015 |
| AIW Services Limited | Professional & scientific | 2025 |
| AJ and SB Associates Limited | Other services | 2017 |
| AJ Bakery Ltd | Wholesale & retail | 2026 |
| AJ Decorating Services Hull Limited | Construction | 2025 |
| AJ Distribution Yorkshire Limited | Transport & logistics | 2025 |
| AJ Driveways Limited | Construction | 2022 |
| AJ Rushby Plumbing and Heating Limited | Construction | 2021 |
| AJA Construction Consultants Ltd | Professional & scientific | 2016 |
| AJA PC Ltd | Construction | 2018 |
| AJB Pipe Services Limited | Construction | 2023 |
| AJD Environmental Ltd | Professional & scientific | 2019 |
| AJE Ltd | Real estate | 2019 |
| AJF Construction Ltd | Construction | 2019 |
| AJF Renewable Services Ltd | Professional & scientific | 2025 |
| Ajfm Security Ltd | Administrative & support | 2026 |
| AJG Hull Limited | Hospitality | 2017 |
| AJH Safety Training Limited | Education | 2023 |
| Ajjs Entertainment Ltd | Hospitality | 2022 |
| AJK Fabrications Ltd | Construction | 2017 |
| AJK Sales Ltd | Wholesale & retail | 2024 |
| AJK Utilities Ltd | Construction | 2026 |
| AJL Motors Ltd | Wholesale & retail | 2023 |
| AJL Plant Hire Ltd | Construction | 2013 |
| AJL Transworld Ltd | Wholesale & retail | 2014 |
| AJP Humberside Limited | Health & social care | 2009 |
| AJR Patient Experience Limited | Professional & scientific | 2024 |
| AJR Premier Joinery Ltd | Construction | 2019 |
| AK Esports UK Limited | Administrative & support | 2023 |
| AK South Yorkshire Limited | Wholesale & retail | 2018 |
| AK Support Ltd | Health & social care | 2024 |
| Akademia Motyli Polish School Ltd | Education | 2023 |
| AKB Property Development Ltd | Real estate | 2025 |
| Akdemir Holdings Limited | Financial services | 2022 |
| Akdeniz Household Goods Ltd | Wholesale & retail | 2025 |
| Akinkunmi Global Venture Ltd | Wholesale & retail | 2025 |
| AKM Spectrum Construct Ltd | Construction | 2024 |
| AKM Team Limited | Wholesale & retail | 2018 |
| Akosua Healthcare Ltd | Health & social care | 2020 |
| AKS Haulage Limited | Transport & logistics | 2018 |
| Akteq Limited | Professional & scientific | 2022 |
| AL Accounting Solutions (Hull) Limited | Professional & scientific | 2013 |
| AL Amal Kids Club Ltd | Education | 2022 |
| AL Electrical Services Limited | Manufacturing | 2015 |
| AL Issa (Hull) Limited | Hospitality | 2020 |
| AL Pacino Pizza Limited | Hospitality | 2021 |
| AL Performance Limited | Professional & scientific | 2022 |
| Al'Pine Clothing Ltd | Wholesale & retail | 2025 |
| Al-Sham Butcher Ltd | Wholesale & retail | 2020 |
| Al-Zahoor Welfare Foundation Ltd | Health & social care | 2017 |
| Alaby Road Hull Nails Ltd | Other services | 2023 |
| Alachi Indian Restaurant Hull Ltd | Hospitality | 2014 |
| Aladdin Square PAN Pizza Limited | Hospitality | 2026 |
| Alal Properties Limited | Wholesale & retail | 2026 |
| Alamgir Consultancy Ltd | Professional & scientific | 2010 |
| Alan Aviation Limited | Transport & logistics | 2009 |
| Alan Vape Ltd | Wholesale & retail | 2026 |
| Alan Wood Holdings Limited | Financial services | 2015 |
| Alanor Services Ltd | Construction | 2017 |
| Alaya Quantum Health Ltd | Health & social care | 2025 |
| Albany Alashhub Ltd | Wholesale & retail | 2023 |
| Albejamo Ltd | Wholesale & retail | 2016 |
| Albemarle Flats(York)Limited | Households | 1968 |
| Albert Draper & SON Limited | Water & waste | 1948 |
| Albert Pike Laundromat Ltd | Other services | 2025 |
| Albert Smart Repair & Body Work Ltd | Wholesale & retail | 2023 |
| Albert's Getaways Ltd | Real estate | 2023 |
| Alberto GIL Locums Ltd | Health & social care | 2013 |
| Albion Audit and Risk Limited | Administrative & support | 2025 |
| Alcool Air Conditioning Ltd | Energy | 2010 |
| Aldenguild Limited | Hospitality | 1982 |