| A Star Legal Consultancy Ltd | Professional & scientific | 2023 |
| A Suggitt Limited | Manufacturing | 1962 |
| A W Abrar Ltd | Health & social care | 2021 |
| A Wadsworth Landscaping Limited | Administrative & support | 2012 |
| A Wadsworth Properties Limited | Real estate | 2025 |
| A&A NE Properties Management Ltd | Real estate | 2024 |
| A&A Properties North East Ltd | Real estate | 2020 |
| A&A Shutters Ltd | Financial services | 2017 |
| A&B Home Care Ltd | Public administration | 2020 |
| A&Dj PUB Group Limited | Hospitality | 2025 |
| A&E Renewables Limited | Professional & scientific | 2025 |
| A&K Helm Properties Ltd | Real estate | 2024 |
| A&L Burgess Estates Ltd Limited | Real estate | 2024 |
| A&M Autos Garage Ltd | Wholesale & retail | 2022 |
| A&M Logistics Limited | Transport & logistics | 2025 |
| A&M Maritime Services Ltd | Transport & logistics | 2022 |
| A&M Taxi Rentals Ltd | Administrative & support | 2024 |
| A&N Safety Consultants Ltd | Professional & scientific | 2021 |
| A&O Scaffolding Ltd | Construction | 2026 |
| A&S Heating & Stoves Ltd | Wholesale & retail | 2022 |
| A&S Property Lettings Ltd | Real estate | 2025 |
| A&S Property Partnership Ltd | Real estate | 2026 |
| A&S Retail PVT Limited | Wholesale & retail | 2025 |
| A&S Venture Holdings Ltd | Financial services | 2025 |
| A&V Completions Ltd | Professional & scientific | 2022 |
| A-Line Floors Ltd | Construction | 2026 |
| A-Sports Management Ltd | Arts & recreation | 2023 |
| A. Carling Plastering Services Ltd | Construction | 2023 |
| A. D. J. Web Properties Ltd | Real estate | 2017 |
| A. Hill & Sons Limited | Agriculture & fishing | 2002 |
| A.Akram Ltd | Hospitality | 2024 |
| A.C. Moule Limited | Health & social care | 2015 |
| A.D Property Maintenance (NE) Ltd | Construction | 2020 |
| A.D Safety Ltd | Professional & scientific | 2026 |
| A.Downes Safety Services Ltd | Professional & scientific | 2016 |
| A.F Delivery Limited | Transport & logistics | 2018 |
| A.I. Employee Ltd | Information & communication | 2025 |
| A.J BAG Property Holding Ltd | Real estate | 2021 |
| A.M. Solutions (NE) Limited | Real estate | 2014 |
| A.N.J Entertainment Limited | Other services | 2023 |
| A.R. Wholesale Limited | Manufacturing | 2020 |
| A.S Fleet Ltd | Transport & logistics | 2025 |
| A.S. Windfarm Services Limited | Professional & scientific | 2011 |
| A.S.T Comms Ltd | Information & communication | 2019 |
| A.Tyler Plumbing&Bathrooms Limited | Construction | 2024 |
| A.V. Dawson Holdings Limited | Real estate | 1998 |
| A.V.Dawson Limited | Transport & logistics | 1959 |
| A.Y Civils and Groundworks Ltd | Construction | 2024 |
| A1 Buses Ltd | Transport & logistics | 2014 |
| A1 Cutz Ltd | Other services | 2025 |
| A1 Electronics and Components Ltd | Wholesale & retail | 2024 |
| A1 Garage Limited | Wholesale & retail | 2014 |
| A1 Hydro-Stop Limited | Construction | 2011 |
| A1 Storage (2021) Ltd | Real estate | 2021 |
| A1 Telecoms Limited | Information & communication | 2022 |
| A1 Training & Safety Limited | Education | 2019 |
| A1 Vehicle Solutions Northeast Limited | Wholesale & retail | 2024 |
| A2Z Driver Solutions Ltd | Transport & logistics | 2025 |
| A3 Biotech Ltd | Health & social care | 2025 |
| A66 Rentals Ltd | Other services | 2017 |
| A66 Tyres Limited | Wholesale & retail | 2001 |
| AA Mahmood Logistics Ltd | Transport & logistics | 2025 |
| AA Property Rentals Ltd | Real estate | 2025 |
| AA Roofing NE Limited | Construction | 2026 |
| AA Utility Experts Limited | Professional & scientific | 2023 |
| Aa&T Estates Limited | Real estate | 2024 |
| AAA Holdings NE Ltd | Real estate | 2024 |
| AAA MOT Ltd | Wholesale & retail | 2025 |
| AAA Offshore Services Ltd | Construction | 2025 |
| AAC Mobile Mechanic Ltd | Manufacturing | 2025 |
| Aadhy PVT Ltd | Wholesale & retail | 2022 |
| Aados Safety Management Limited | Professional & scientific | 2024 |
| AAG Ents Ltd | Hospitality | 2019 |
| AAG Property Limited | Real estate | 2019 |
| AAK Food Durham Ltd | Hospitality | 2024 |
| Aakfi Limited | Real estate | 2025 |
| Aalmi Majlis Tahaffuz Khatm E Nubuwwat UK CIC | Public administration | 2025 |
| Aapna Services Limited | Health & social care | 2010 |
| Aaris Private Ltd | Wholesale & retail | 2018 |
| Aarm Services Limited | Construction | 2024 |
| AARONH33 Ltd | Transport & logistics | 2026 |
| AARU6 Technologies Limited | Information & communication | 2019 |
| Aascend Limited | Wholesale & retail | 2025 |
| AB Construction & Plastering Limited | Construction | 2024 |
| AB Joinery Solutions Ltd | Construction | 2024 |
| AB Logistics Solutions Ltd | Transport & logistics | 2026 |
| AB Visa Consultants Limited | Administrative & support | 2022 |
| AB10 Engineering Ltd | Professional & scientific | 2021 |
| Abaxter Inspection Ltd | Construction | 2026 |
| Abbas Brothers Enterprises Ltd | Wholesale & retail | 2025 |
| Abbas Superstore Ltd | Wholesale & retail | 2025 |
| Abbcc Ltd | Hospitality | 2019 |
| Abbey Electrical and Mechanical Engineering Limited | Construction | 2002 |
| Abbey Industrial Services Limited | Construction | 2023 |
| Abbey Joinery and Manufacture Limited | Construction | 2019 |
| Abbie JO Limited | Wholesale & retail | 2025 |
| Abbzfit Elite Ltd | Other services | 2026 |
| Abbzfit Online Ltd | Other services | 2021 |
| ABC Fire Safety Security Ltd | Professional & scientific | 2026 |
| Abdulhakeem Trade & Distribution Ltd | Wholesale & retail | 2025 |