| A&K ALL Star Brickwork Ltd | Construction | 2025 |
| A&M Landscaping NE Ltd | Administrative & support | 2019 |
| A&M UK Investment Ltd | Real estate | 2023 |
| A&R Roofing and Home Improvement Ltd | Construction | 2021 |
| A&T Consultancy (NE) Ltd | Professional & scientific | 2022 |
| A&T Waste Management Limited | Water & waste | 2020 |
| A-Four Business Equipment Limited | Wholesale & retail | 1998 |
| A. S. Tyres Limited | Wholesale & retail | 1984 |
| A.A. Letting Ltd | Real estate | 2003 |
| A.A.S. Contractors Ltd | Construction | 2021 |
| A.D.J Motors Ltd | Wholesale & retail | 2025 |
| A.G (Gateshead) Ltd | Wholesale & retail | 2018 |
| A.G. Mallinson GAS, Plumbing & Heating Limited | Construction | 2017 |
| A.H.&C.R. Transport Ltd | Transport & logistics | 2019 |
| A.K.B.J. Limited | Real estate | 2021 |
| A.M Executive Cars Limited | Wholesale & retail | 2024 |
| A.S Renewable Services Ltd | Manufacturing | 2023 |
| A.T.S. Electro-Lube (UK) Limited | Wholesale & retail | 1992 |
| A.Vickers Electrical Ltd | Construction | 2015 |
| A1 Chinuch Limited | Education | 2011 |
| A1 Double Glazing Repairs Ltd | Construction | 2011 |
| A1 Elite Motorcycle Training Ltd | Education | 2024 |
| A1 Energy Efficient Homes Ltd | Construction | 2018 |
| A1 Energy Efficient Windows Limited | Construction | 2018 |
| A1 Pallets Wood Recycling Ltd | Manufacturing | 2020 |
| A1 Prime Foods Ltd | Wholesale & retail | 2022 |
| A1 Sales & Marketing Ltd | Wholesale & retail | 2010 |
| A1 Windows (Gateshead) Ltd | Manufacturing | 2011 |
| A19 Film and Video Limited | Information & communication | 1986 |
| A2B Capital Holdings Limited | Professional & scientific | 2024 |
| A2B Recycling Ltd | Water & waste | 2025 |
| A2Z Delivery Logistics Ltd | Transport & logistics | 2026 |
| A2Z Licensing (David Wilson) Limited | Professional & scientific | 2019 |
| A2Z Licensing (UK) Limited | Professional & scientific | 2016 |
| A2Z Litigation Support Limited | Professional & scientific | 2018 |
| A4 Properties Ltd | Real estate | 2003 |
| AA (NE) Property Ltd | Real estate | 2019 |
| AA Construction (North East) Ltd | Construction | 2008 |
| AA Property (NE) Ltd | Real estate | 2025 |
| AA35R Limited | Construction | 2026 |
| AAA Holdings Northeast Ltd | Real estate | 2017 |
| Aaeot Limited | Extraterritorial | 2022 |
| Aagg Construction Ltd | Construction | 2023 |
| Aaron KAI Ltd | Wholesale & retail | 2020 |
| Aarons Express Store Ltd | Wholesale & retail | 2020 |
| Aatif Hashmi Consultancy Ltd | Professional & scientific | 2019 |
| Aatiqah Boutique Spa Ltd | Other services | 2012 |
| AB & CK Investments Ltd | Real estate | 2023 |
| AB Beauty & Aesthetics Limited | Other services | 2021 |
| AB Pure Cleaning Service Limited | Administrative & support | 2025 |
| AB Technical & Offshore Services Ltd | Professional & scientific | 2018 |
| Abacus Interactive Media Limited | Professional & scientific | 2001 |
| Abacus Traffic Surveys Ltd | Administrative & support | 2015 |
| Abbey Accountancy Services (North East) Limited | Administrative & support | 2009 |
| Abbey Headstones Ltd | Manufacturing | 2025 |
| Abbey Philanthropy Initiatives Ltd | Professional & scientific | 2015 |
| Abbeyview Housing Ltd | Construction | 2021 |
| Abco - Anderson Beverage Co. Ltd | Wholesale & retail | 2003 |
| Abco Anderson Beverage Co Property Limited | Other services | 2016 |
| Abdul Dunston Ltd | Hospitality | 2026 |
| Abdul Quraishi Consultancy Limited | Health & social care | 2017 |
| Abercromby Estates Limited | Real estate | 2019 |
| Abers Holdings Ltd | Real estate | 2024 |
| Abhinandan Consulting Limited | Professional & scientific | 2008 |
| Able 2 Electrical Limited | Construction | 2015 |
| Able Holdings (NE) Limited | Financial services | 2025 |
| Able Holdings (Northern) Limited | Professional & scientific | 2004 |
| Ably Properties Ltd | Real estate | 2022 |
| ABN Trust | Other services | 2024 |
| Aboc Properties Limited | Real estate | 2025 |
| Above and Beyond Property Limited | Construction | 2020 |
| ABP Renewables Ltd | Energy | 2025 |
| ABR Alterations, Building & Roofing Ltd | Construction | 2006 |
| ABS Car Sales Ltd | Wholesale & retail | 2023 |
| ABS Precision Limited | Manufacturing | 2004 |
| Absolute Wholesale Limited | Wholesale & retail | 2017 |
| ABU MO Locum Ltd | Wholesale & retail | 2022 |
| ABW (NE) Limited | Real estate | 2018 |
| AC Agencies Limited | Administrative & support | 2009 |
| Academy Geomatics Limited | Professional & scientific | 2001 |
| Acas Kitchens and Interiors Ltd | Manufacturing | 2023 |
| Acbc Cardiology Tees Limited | Health & social care | 2025 |
| Accenturio Ltd | Real estate | 2018 |
| Access Housing Management Services Limited | Real estate | 2015 |
| Access Loft Storage Limited | Construction | 2004 |
| Access North East Ltd | Construction | 2023 |
| Access Training Limited | Administrative & support | 1989 |
| Accessible Scaffolding Limited | Construction | 2016 |
| Ace Circus Productions Limited | Arts & recreation | 2011 |
| Ace Foods (NE) Ltd | Other services | 2024 |
| Ace Joinery (N.E.) Limited | Manufacturing | 2003 |
| Ace Mold UK Ltd | Manufacturing | 2010 |
| Aceparts Limited | Professional & scientific | 2014 |
| Achievers Professionals Limited | Professional & scientific | 2024 |
| ACI NE Ltd | Construction | 2024 |
| ACL Property Maintenance (NE) Ltd | Real estate | 2023 |
| Acomb Avenue (Seaton Delaval) Management Company Limited | Households | 1997 |
| Acorn Bookkeeping and Accounting Services Limited | Professional & scientific | 2012 |
| Acors (NE) Ltd | Wholesale & retail | 2018 |
| Acrehall Services Ltd | Professional & scientific | 2009 |