| Alphin Catering Ltd | Hospitality | 2002 |
| Alphin Enterprises Ltd | Agriculture & fishing | 2019 |
| Alphin Ltd | Professional & scientific | 2014 |
| Alphin Property Ltd | Other services | 2015 |
| Alpin UK Limited | Other services | 2005 |
| ALS Consulting Ltd | Other services | 2023 |
| Alsium Limited | Professional & scientific | 2018 |
| Alternative Direct Marketing Limited | Agriculture & fishing | 1995 |
| Altitude Accommodation Ltd | Real estate | 2025 |
| Alumino UK Limited | Manufacturing | 2007 |
| AM & TL Wade Holdings Ltd | Financial services | 2018 |
| Amak Maintenance Limited | Construction | 2022 |
| Amara Holdings Ltd | Real estate | 2023 |
| AMARIS18-PROPERTY Limited | Real estate | 2026 |
| Amazing Acorns Day Nursery Limited | Health & social care | 2017 |
| Amazing Gates & Barriers Ltd | Manufacturing | 2025 |
| Amber Chair Frames Limited | Manufacturing | 2014 |
| Ambiental Trans Limited | Transport & logistics | 2021 |
| Ambikeskool Ltd | Education | 2019 |
| Ambra Corporation Europe Limited | Administrative & support | 2009 |
| Ambuserv Limited | Transport & logistics | 2014 |
| AMD Electric Limited | Manufacturing | 2018 |
| Amedro Holdings Limited | Real estate | 2025 |
| Amen Band Limited | Arts & recreation | 2025 |
| Amethyst Star Limited | Health & social care | 2013 |
| Ametys Ltd | Wholesale & retail | 2020 |
| Amgrace EV Limited | Wholesale & retail | 2021 |
| Amgrace Limited | Other services | 2016 |
| Amgrace Lowdham Limited | Wholesale & retail | 2021 |
| Amgrace Nottm Limited | Other services | 2017 |
| AMI Financial Products Ltd | Financial services | 2014 |
| Amifp Ltd | Wholesale & retail | 2025 |
| Amiri Holdings Ltd | Real estate | 2023 |
| Amiri Property Management Limited | Real estate | 2025 |
| Amiri Rentals Limited | Wholesale & retail | 2025 |
| Ammonite Residentials Ltd | Real estate | 2023 |
| Amokabel Flexishield Ltd | Manufacturing | 2003 |
| Amorgan Contractors Ltd. | Construction | 2018 |
| Ampanova Limited | Wholesale & retail | 2013 |
| Amritanjali Limited | Health & social care | 2011 |
| AMS Financial Consulting Limited | Financial services | 2013 |
| Amusadege Ltd | Construction | 2023 |
| AN Carpentry Services Ltd | Construction | 2025 |
| Ananya & Ananya PVT Ltd | Real estate | 2023 |
| Anchor Children Services CIC | Health & social care | 2026 |
| Anchorstead Therapy Limited | Public administration | 2026 |
| Anderton Investments Ltd | Real estate | 2026 |
| Andiana Ltd | Wholesale & retail | 2023 |
| Andra Ethan Annalise Limited | Health & social care | 2016 |
| Andreou Properties Limited | Real estate | 2017 |
| Andrew Edward Hair Ltd. | Other services | 2023 |
| Andrew Goward Limited | Construction | 2018 |
| Andrew Roberts Joinery Ltd | Construction | 2016 |
| Andy Clark Physiotherapy Limited | Health & social care | 2015 |
| Andy Tewson Agencies Limited | Wholesale & retail | 2003 |
| Andycare Ltd | Health & social care | 2017 |
| Anexgen (Fire Protection and Drylining Specialists) Limited | Construction | 2019 |
| Angel Nails Mansfield Limited | Other services | 2021 |
| Angel Sets UK Limited | Other services | 2024 |
| Angel Wings Pet Crematorium Ltd | Other services | 2026 |
| Angels Gym Ltd | Arts & recreation | 2012 |
| Angels Passive Fire Ltd | Construction | 2026 |
| Angler Inventory Limited | Information & communication | 2023 |
| Anguo Social Care Ltd | Health & social care | 2020 |
| Angyal Logistics Ltd | Transport & logistics | 2025 |
| Anhad(Mansfield) Ltd | Hospitality | 2025 |
| Anis & Sons Ltd | Wholesale & retail | 2024 |
| Anisino Consultancy Limited | Information & communication | 2019 |
| Anna Salach Ltd | Extraterritorial | 2024 |
| Annmarie Mcclintock Consultancy Ltd | Professional & scientific | 2019 |
| Anthony Summerfield Limited | Financial services | 2015 |
| Anyong Limited | Information & communication | 2014 |
| AO Group and Services Limited | Professional & scientific | 2017 |
| AP INT Ltd | Hospitality | 2026 |
| AP Racing Engines Limited | Wholesale & retail | 2012 |
| AP Services Group Ltd | Construction | 2022 |
| Apa.Estates Limited | Real estate | 2023 |
| APC Accountants Limited | Professional & scientific | 2007 |
| APC Holdings Limited | Financial services | 2018 |
| APC Offices Limited | Administrative & support | 2015 |
| Apex Conveyor Services Ltd | Construction | 2025 |
| Apex Developments U.K Ltd | Construction | 2017 |
| Apex Facilities Group Limited | Construction | 2024 |
| Apex Management Consulting Limited | Professional & scientific | 2024 |
| Apex NDT Inspections Ltd | Professional & scientific | 2021 |
| Apex Quality Inspections Ltd | Professional & scientific | 2025 |
| Apex Transport Group Limited | Transport & logistics | 2025 |
| APH (Midlands) Properties Limited | Real estate | 2025 |
| APH Midlands Limited | Professional & scientific | 2017 |
| Apis RA Limited | Hospitality | 2017 |
| Apparel Software Limited | Information & communication | 2012 |
| Aquacopia Ltd | Manufacturing | 2024 |
| Aqualawn Ltd | Professional & scientific | 2016 |
| Aquatopia Consulting Ltd | Professional & scientific | 2015 |
| AR and SH C.Warsop Limited | Transport & logistics | 2017 |
| AR BUS and Coach Ltd | Wholesale & retail | 2026 |
| AR Investments Nottingham Ltd | Real estate | 2020 |
| AR11 Trading Ltd | Wholesale & retail | 2021 |
| Arabas Ltd | Real estate | 2022 |
| Arabu Transcom Ltd | Transport & logistics | 2025 |