| 1ST AID Commercials Ltd | Wholesale & retail | 2014 |
| 24CT. Beauty Ltd | Other services | 2017 |
| 2TONE Photography Limited | Professional & scientific | 2013 |
| 32 Puente 2 Limited | Extraterritorial | 2014 |
| 40 AM Ltd | Real estate | 2021 |
| 5CM Limited | Real estate | 2023 |
| 6OU Limited | Real estate | 2021 |
| A & C Storey Groundworks Ltd | Construction | 2022 |
| A & M Window Installation Limited | Construction | 2022 |
| A Shan Fast Food 2 Ltd | Hospitality | 2025 |
| A&S Portfolio Holdings Ltd | Real estate | 2026 |
| A. Bureau (2021) Ltd | Professional & scientific | 2021 |
| A.B.B. Developments Limited | Construction | 2006 |
| A.E.G Management Limited | Professional & scientific | 2024 |
| A.H. & D. Cuthbertson Limited | Wholesale & retail | 1961 |
| Aadhesh PVR Ltd | Real estate | 2020 |
| AAM Beamish Ltd | Real estate | 2016 |
| Aarna Services Ltd | Wholesale & retail | 2020 |
| Accapi Ltd | Wholesale & retail | 2013 |
| Accept Training Ltd | Administrative & support | 2024 |
| Ace Pizza DH9 Ltd | Hospitality | 2025 |
| Ace Pizza Stanley Ltd | Hospitality | 2024 |
| Acer Components & Coatings Limited | Construction | 2018 |
| Adaptive Ocean Academy CIC | Education | 2023 |
| Adcaptures Collectives Ltd | Information & communication | 2025 |
| Addcity Limited | Real estate | 2021 |
| Addiamo Ltd | Wholesale & retail | 2021 |
| Adentalis Ltd | Education | 2015 |
| Adinfra UK Limited | Professional & scientific | 2024 |
| Advanced Decorating Limited | Construction | 2026 |
| AEK Estates Limited | Real estate | 2019 |
| AG Compressed Air Limited | Energy | 2014 |
| AG Controls Ltd | Manufacturing | 2018 |
| AIC Capital & Asset Management Limited | Real estate | 2020 |
| Aimme United Co. Limited | Real estate | 2019 |
| Ajt&Son Ltd | Manufacturing | 2022 |
| AKM Landscaping Ltd | Administrative & support | 2022 |
| AL & EM Limited | Transport & logistics | 2016 |
| ALA Pharma Ltd | Health & social care | 2013 |
| ALA Spicery Ltd | Hospitality | 2016 |
| ALA Spicery NE Ltd | Hospitality | 2025 |
| Alan Oxley Builders Limited | Construction | 2003 |
| Alan Scott Ltd | Manufacturing | 2023 |
| Alan Small Financial Services Limited | Financial services | 2015 |
| Alexander James Specialist Cars Ltd | Wholesale & retail | 2024 |
| Alexander Travel Ltd | Administrative & support | 2025 |
| Alfred Pallas Limited | Real estate | 2014 |
| Alimart Limited | Professional & scientific | 2014 |
| ALL Steel Tank Company Ltd | Manufacturing | 2025 |
| Allflex UK Group Limited | Manufacturing | 2010 |
| Alma Meadow Glamping Ltd | Hospitality | 2023 |
| Aloo Gobi Whala Limited | Wholesale & retail | 2014 |
| Alpha Roofline Ltd | Construction | 2019 |
| Alstriver Limited | Real estate | 2024 |
| AM Diagnostic Imaging Ltd | Health & social care | 2021 |
| AM Europe Limited | Real estate | 2020 |
| Amador Christie Design Ltd | Professional & scientific | 2025 |
| AMC Plant and Tool Hire Ltd | Administrative & support | 2026 |
| Amethyst Aesthetics Limited | Health & social care | 2018 |
| Amica Concept Limited | Real estate | 2020 |
| Andaura Limited | Manufacturing | 2008 |
| Andy Pollard Plumbing & Heating Limited | Construction | 2018 |
| Annfield Barbers Limited | Other services | 2023 |
| Annfield Car & Commercial Limited | Wholesale & retail | 2018 |
| Annfield Local Store Limited | Wholesale & retail | 2025 |
| Annfield Plain Cricket Club Limited | Arts & recreation | 2001 |
| Annfield Tandoori Ltd | Hospitality | 2021 |
| Anthony Ohanlon Limited | Construction | 2018 |
| Apex Ability Gear Limited | Other services | 2020 |
| Apex Trade Frames Ltd | Manufacturing | 2026 |
| APL Property Solutions Limited | Real estate | 2019 |
| Aquarod Ltd | Water & waste | 2021 |
| Aquila 82 UK Ltd | Real estate | 2023 |
| Arc-Up Welding Services Limited | Manufacturing | 2015 |
| Artsi Ltd | Professional & scientific | 2018 |
| Ascent Academy Ltd | Education | 2026 |
| Astravaganza Entertainment Ltd | Arts & recreation | 2013 |
| AT & MC Limited | Wholesale & retail | 2021 |
| Atlas C & J Limited | Real estate | 2021 |
| Atous Management Limited | Real estate | 2023 |
| Aurora Projects Limited | Professional & scientific | 2025 |
| Aurora Vehicle Services Ltd | Wholesale & retail | 2024 |
| Aviron Construction Ltd | Construction | 2024 |
| AYE AYE Captain Limited | Other services | 2021 |
| B & S Maintenance (North East) Limited | Construction | 2014 |
| B a C Technical Limited | Professional & scientific | 2010 |
| B Nailed Joinery Ltd | Construction | 2026 |
| B.Cutmore Electrical Services Limited | Construction | 2026 |
| B.R. Distribution Limited | Wholesale & retail | 2001 |
| B2B Wood Products Limited | Wholesale & retail | 2012 |
| Bambinos NE Ltd | Wholesale & retail | 2012 |
| Band Pencil Ltd | Information & communication | 2024 |
| Bang Tidy Cleaners Ltd | Administrative & support | 2025 |
| Barbell Betties Limited | Other services | 2013 |
| Barkybites Ltd | Wholesale & retail | 2025 |
| Bayberry Hollow Limited | Wholesale & retail | 2013 |
| Bbss Property Limited | Real estate | 2023 |
| Beamish Extras Ltd | Other services | 2019 |
| Beamish Glamping Ltd | Hospitality | 2020 |
| Beamish Hall Limited | Hospitality | 2000 |