| Apras Group Ltd | Construction | 2023 |
| Apras Solutions Ltd | Construction | 2025 |
| Aprion Partners Consulting Ltd | Professional & scientific | 2025 |
| APS Legacy Ltd | Professional & scientific | 2023 |
| AQ Rent UK Ltd | Administrative & support | 2000 |
| Aquavibe Valeting & Logistics Ltd | Transport & logistics | 2025 |
| AR Engineering Services Ltd | Construction | 2025 |
| Aradaan Limited | Administrative & support | 2024 |
| Arch & Artistry Limited | Other services | 2025 |
| Arch Consulting Services NE Ltd | Information & communication | 2024 |
| Archrise (Staffing) Ltd | Administrative & support | 2016 |
| Ardelleaccommodation Ltd | Real estate | 2026 |
| ARH Residential Ltd | Real estate | 2024 |
| Aristou Family Holdings Ltd | Real estate | 2016 |
| Aristou Family Partnership LLP | | 2016 |
| Arkana Technology Limited | Wholesale & retail | 2022 |
| Arkana Traders Limited | Wholesale & retail | 2023 |
| Arklow Ltd | Financial services | 2021 |
| Arlo Refurb Ltd | Real estate | 2024 |
| Armcad Ltd | Professional & scientific | 2021 |
| Armstrong Consultancy Services (Acsl) Limited | Professional & scientific | 2009 |
| Armstrong Direct Limited | Wholesale & retail | 2005 |
| Arnewood Property Holdings Ltd | Real estate | 2024 |
| Arnewood Property Solutions Ltd | Real estate | 2024 |
| Arrowbuild & Civil Engineering Limited | Construction | 2009 |
| Arrowcruit Holdings Limited | Financial services | 2010 |
| Arrowcruit Limited | Construction | 2005 |
| Arrowflow Limited | Other services | 2018 |
| Arrowhaul & Plant Hire Limited | Transport & logistics | 2009 |
| Arthousing Family Holdings Ltd | Real estate | 2018 |
| Arthousing Family Partnership LLP | | 2018 |
| Arvind Locums Ltd | Health & social care | 2010 |
| ARY Pizza Ltd | Hospitality | 2022 |
| AS Managment Ltd | Professional & scientific | 2018 |
| ASD UK Investments Limited | Real estate | 2024 |
| ASG Family Holdings Ltd | Real estate | 2023 |
| ASG Ventures LLP | | 2023 |
| Ashbrook Construction Services Limited | Construction | 2003 |
| Ashkan Homes LLP | | 2020 |
| Ashkan Limited | Households | 2020 |
| Ashley Guest Houses Limited | Hospitality | 2004 |
| ASN Finance LLP | | 2020 |
| ASN Holdings Ltd | Real estate | 2020 |
| Asohp Limited | Health & social care | 2025 |
| Aspire UK Developments LLP | | 2019 |
| Asplin North East Limited | Education | 2014 |
| Asset Integrity Limited | Professional & scientific | 2015 |
| Assets Together Limited | Real estate | 2017 |
| Associated Property Investment Limited | Extraterritorial | 2017 |
| Atlanta Shipping Ltd | Transport & logistics | 2019 |
| Atlas NE Ltd | Health & social care | 2024 |
| Atpn Medical Services Ltd | Health & social care | 2023 |
| Atscale Digital Limited | Professional & scientific | 2023 |
| Attained Group Limited | Information & communication | 2022 |
| Augustus Blanche Holdings Ltd | Real estate | 2018 |
| Augustus Distribution Ltd | Wholesale & retail | 2024 |
| Aura Dental Group Limited | Health & social care | 2021 |
| Auracle Advisory Limited | Professional & scientific | 2024 |
| Auroute Ltd | Information & communication | 2026 |
| Auroxeon Limited | Information & communication | 2026 |
| Ausmats Consultancy Limited | Health & social care | 2013 |
| Automation With Control Ltd | Information & communication | 2006 |
| Automotional Ltd | Administrative & support | 2006 |
| Avenford Apparel Ltd | Wholesale & retail | 2026 |
| AW Safety and Compliance Ltd | Professional & scientific | 2022 |
| AW Wellness Studios Ltd | Arts & recreation | 2020 |
| AWE Family Partnership LLP | | 2020 |
| Awuah K Limited | Households | 2025 |
| Axiom Family Holdings Ltd | Real estate | 2021 |
| Axiom Partnership LLP | | 2021 |
| AYE Ltd | Financial services | 2025 |
| Azatom Group Limited | Manufacturing | 2004 |
| Azzurri Automation Limited | Information & communication | 2011 |
| B & D Gill WP Ltd | Administrative & support | 2024 |
| B & W Lifting Ltd | Manufacturing | 2011 |
| B & W Transport Services Limited | Transport & logistics | 2017 |
| B C Enterprise (North East) Limited | Hospitality | 2017 |
| B Chen & Y XU WP Ltd | Administrative & support | 2024 |
| B Clarke WP Ltd | Administrative & support | 2024 |
| B Worton Engineering Limited | Professional & scientific | 2026 |
| B. James Properties Ltd. | Real estate | 1999 |
| B. K Services (NE) Ltd | Construction | 2016 |
| BA Group (North East) Limited | Financial services | 2025 |
| Bacon Family Holdings Ltd | Real estate | 2017 |
| Bacon Family Partnership LLP | | 2017 |
| Badejo Family Holdings Ltd | Real estate | 2017 |
| Badejo Family Partnership LLP | | 2017 |
| Badge Global Ltd | Financial services | 2025 |
| Bailey Group Umbrella Company Ltd | Professional & scientific | 2017 |
| Baileyluxe Ltd | Wholesale & retail | 2026 |
| Bainbridge Family Holdings Limited | Real estate | 2019 |
| Bainbridge Family Partnership LLP | | 2019 |
| Baker Category and Shopper Solutions Ltd | Professional & scientific | 2021 |
| Balbir Ltd | Health & social care | 2018 |
| Balfour Accommodation Ltd | Real estate | 2022 |
| Balquhidder Group Limited | Financial services | 2022 |
| Balquhidder Investments Limited | Financial services | 2022 |
| Balquhidder Services Limited | Professional & scientific | 2022 |
| Bambino Investments Limited | Construction | 2020 |
| Bamburgh (2023) Ltd | Real estate | 2023 |