| 10AY Ltd | Wholesale & retail | 2024 |
| 14 Years Ltd | Information & communication | 2024 |
| 17 Seventeen Design Ltd | Wholesale & retail | 2025 |
| 235 High Street Limited | Wholesale & retail | 2016 |
| 5640 Limited | Information & communication | 2008 |
| 5TH Element JIU Jitsu Academy CIC | Arts & recreation | 2024 |
| 74 South Ltd | Financial services | 2022 |
| A C Business Services Limited | Professional & scientific | 2020 |
| A Clarke Flooring Limited | Construction | 2025 |
| A Hunter Groundworks Limited | Construction | 2015 |
| A I Electrical Engineering Limited | Construction | 2023 |
| A1 Crown Takeaway Ltd | Hospitality | 2021 |
| AA Haulage NE Limited | Transport & logistics | 2024 |
| AAA Property NE Limited | Real estate | 2025 |
| Abley Groundworks Limited | Construction | 2015 |
| Abley Lettings Limited | Real estate | 2021 |
| ACA Properties NE Ltd | Real estate | 2022 |
| Accudrive Ltd | Administrative & support | 2023 |
| Acearium Global Ltd | Wholesale & retail | 2025 |
| ACH Plumbing & Heating Specialists Limited | Construction | 2020 |
| Acorn Training Consultants Limited | Education | 1996 |
| Acute Developments Ltd | Construction | 2025 |
| Aditya Diagnostic LAB Limited | Health & social care | 2024 |
| Admur Developments Ltd Ltd | Real estate | 2022 |
| Adovan Ltd | Wholesale & retail | 2025 |
| Advance Learning Partnership | Education | 2012 |
| Advanced Driveway Solutions Limited | Construction | 2022 |
| Aesthetic Meducation Limited | Extraterritorial | 2023 |
| AFI Co. Limited | Construction | 2020 |
| Afterglow Sunbeds (NE) Limited | Other services | 2025 |
| AG Motorserve Ltd | Wholesale & retail | 2018 |
| AHS Shop Limited | Wholesale & retail | 2025 |
| Airtime LAB Limited | Information & communication | 2025 |
| AJM Projects Limited | Construction | 2015 |
| AJO Lettings Ltd | Real estate | 2024 |
| AKP Diagnostics Ltd | Health & social care | 2025 |
| AL Briya Trading Ltd | Wholesale & retail | 2026 |
| Alchemology Ltd | Wholesale & retail | 2024 |
| Alderson Gray & Foggin Ltd | Hospitality | 2025 |
| Ali's Pizzeria Ltd | Hospitality | 2025 |
| Alka Global Ltd | Wholesale & retail | 2026 |
| Allora Trade Ltd | Wholesale & retail | 2025 |
| Alminasperfumes Ltd | Wholesale & retail | 2026 |
| ALP Active Limited | Education | 2011 |
| ALYA11 Ltd | Wholesale & retail | 2024 |
| AMG Training Limited | Administrative & support | 2015 |
| AMY Cairns Limited | Public administration | 2025 |
| Anderson Consulting North East Limited | Administrative & support | 2018 |
| Anderson Fleet Services Limited | Transport & logistics | 2017 |
| Anderson Remounts Limited | Wholesale & retail | 2019 |
| Andmur Construction Ltd | Real estate | 2020 |
| Andrew Burn Steel Fabrications Limited | Manufacturing | 2003 |
| Andrew Parnaby Mobility Services Limited | Other services | 2000 |
| Andy Paisley Golf Ltd | Education | 2024 |
| Annemaries Funeral Services Limited | Other services | 2024 |
| Another Jukebox Ltd | Wholesale & retail | 2025 |
| Antalya Barbers Spennymoor Ltd | Other services | 2025 |
| Antrec Limited | Education | 2011 |
| AP Brickwork & Construction Limited | Construction | 2024 |
| APD NE Ltd | Professional & scientific | 2021 |
| APH Civils & Earthworks Limited | Administrative & support | 2022 |
| Arcas Consulting Ltd | Professional & scientific | 2023 |
| Ardelean Haulage Ltd | Transport & logistics | 2019 |
| Aries Collective Store Ltd | Wholesale & retail | 2026 |
| Arlington (West Hartford) Limited | Real estate | 2014 |
| Arlington Holding Group Ltd | Real estate | 2017 |
| Arlington Homes Ltd | Real estate | 2019 |
| Arlington Property (North East) LLP | | 2007 |
| Arlington Real Estate (Homes) Limited | Real estate | 2015 |
| Arlington Real Estate (Investments) Limited | Real estate | 2016 |
| Arlington Real Estate (York Central) Ltd | Real estate | 2006 |
| Arlington Real Estate Limited | Real estate | 2011 |
| Artful INK Limited | Arts & recreation | 2003 |
| Arvion Trade Ltd | Wholesale & retail | 2026 |
| Asgard 2.0 Ltd | Wholesale & retail | 2020 |
| Astrolec Ltd | Construction | 2021 |
| Asya Bazaar Ltd | Wholesale & retail | 2026 |
| Atlasbridge Ltd | Wholesale & retail | 2025 |
| Atrock Ltd | Wholesale & retail | 2025 |
| ATT Fabrications Limited | Manufacturing | 2008 |
| Attention 2 Detail Car Care Limited | Wholesale & retail | 2024 |
| AU Commerce Ltd | Wholesale & retail | 2026 |
| Austin Pickering Heating Limited | Construction | 2006 |
| Auto Solutions NE Ltd | Wholesale & retail | 2025 |
| Automotive and Electrical Systems Limited | Wholesale & retail | 2019 |
| Auton Academy Limited | Education | 2020 |
| Autovex Ltd | Wholesale & retail | 2026 |
| AUX Studios Ltd | Professional & scientific | 2016 |
| Avec Sport Limited | Administrative & support | 2001 |
| Avenue Builders and Landscapers Ltd | Administrative & support | 2014 |
| Ayem Global Ltd | Wholesale & retail | 2025 |
| Aysevar Ltd | Wholesale & retail | 2026 |
| Aysvera Ltd | Wholesale & retail | 2025 |
| B & G Taylor (North East) Limited | Real estate | 1979 |
| Babyhig Ltd | Wholesale & retail | 2025 |
| Baileys Blinds Limited | Wholesale & retail | 1993 |
| Baki Mega Ltd | Wholesale & retail | 2025 |
| Baltic Wood Ltd | Construction | 2021 |
| Bargain Smelly Ltd | Wholesale & retail | 2015 |
| Baris Altinsoy Ltd | Wholesale & retail | 2026 |