| Adips International Ltd | Extraterritorial | 2008 |
| Adips Limited | Arts & recreation | 2003 |
| Adips Training Ltd | Extraterritorial | 2008 |
| ADK Recruitment Services Ltd | Administrative & support | 2016 |
| Adkins & Cheurfi North Ltd | Administrative & support | 2024 |
| Adkins & Cheurfi Recruitment Ltd | Administrative & support | 2016 |
| Admin 4U Limited | Administrative & support | 2008 |
| Administration Partners Group (APG) Ltd | Administrative & support | 2026 |
| Adorathy Limited | Professional & scientific | 2025 |
| Adubiaro Foods Ltd | Wholesale & retail | 2020 |
| Advacent Academy Ltd | Education | 2020 |
| Advance Door Centre Ltd | Wholesale & retail | 2013 |
| Advance Door Centre Trustee Ltd | Financial services | 2026 |
| Advance Physio Solutions Ltd | Health & social care | 2003 |
| Advance Service Technology Co. Ltd | Extraterritorial | 2020 |
| Advanced Blade Repair Services Ltd | Administrative & support | 2014 |
| Advanced Engravers (NE) Ltd | Professional & scientific | 2018 |
| Advanced Floors Limited | Construction | 2022 |
| Advanced GAS & Power Ltd | Energy | 2023 |
| Advanced Home Improvements NE Ltd | Manufacturing | 2025 |
| Advanced IFA Ltd | Financial services | 2004 |
| Advanced Wealth Management Limited | Financial services | 2026 |
| Advanta Heat Ltd | Construction | 2024 |
| Adventure Sunderland | Education | 1996 |
| Adversity Games Ltd. | Information & communication | 2016 |
| AEC Property Group Ltd | Real estate | 2025 |
| AEC Retail Solutions Ltd | Wholesale & retail | 2026 |
| Aerobotics UAS Ltd | Professional & scientific | 2016 |
| Aesc Apollo Holding Limited | Financial services | 2023 |
| Aesc Atlantic Holding Limited | Financial services | 2022 |
| Aesc UK Holding Limited | Financial services | 2023 |
| Aesc UK Plant 1 Limited | Manufacturing | 2017 |
| Aesc UK Plant 2 Holding Limited | Manufacturing | 2024 |
| Aesc UK Plant 2 Limited | Manufacturing | 2022 |
| Aesthetic Beauty Centre (UK) Ltd | Health & social care | 2013 |
| Aesthetic Beauty Centre LLP | | 2002 |
| Aestian Ltd | Administrative & support | 2017 |
| Aether Medical Services Ltd | Health & social care | 2026 |
| Affinity Advice Ltd | Financial services | 2022 |
| Affordable Home Essentials Sunderland Ltd | Wholesale & retail | 2025 |
| Afgd Ltd | Wholesale & retail | 2013 |
| AFL Holdings Ltd | Construction | 2025 |
| Afomato (NE) Ltd | Hospitality | 2024 |
| African-Caribbean Community Association North East CIC | Administrative & support | 2022 |
| Africana by Deckup Limited | Wholesale & retail | 2026 |
| Afrikana Hub Ltd | Wholesale & retail | 2023 |
| Afriwest Pride Ltd | Real estate | 2023 |
| Afro-Hair World and Cosmetics Ltd | Wholesale & retail | 2025 |
| Afrocrave Kitchen Ltd | Manufacturing | 2026 |
| Afrolink Ltd | Administrative & support | 2018 |
| AFT Milfield Limited | Other services | 2021 |
| AG Plastering & Rendering Ltd | Construction | 2021 |
| AGA Engineering Services Ltd | Professional & scientific | 2022 |
| Agbabola Limited | Public administration | 2025 |
| Agdh Property Group Ltd | Real estate | 2025 |
| AGE UK Sunderland | Health & social care | 2001 |
| AGE UK Sunderland Services Limited | Financial services | 1996 |
| Agim Property Services Ltd | Construction | 2026 |
| AGL Property (NE) Limited | Real estate | 2020 |
| AGM Developments (Carliol Tower) Limited | Construction | 2017 |
| AGP Decorators Limited | Construction | 2015 |
| AH Recovery & Towing Ltd | Transport & logistics | 2024 |
| Ahmad Travels Ltd | Administrative & support | 2017 |
| Ahmed Barbers Ltd | Other services | 2017 |
| Ahmed Property Sunderland Limited | Real estate | 2025 |
| Ahmedrizq Ltd | Hospitality | 2025 |
| AHR & Sons Ltd | Wholesale & retail | 2024 |
| AIA Alphabets Ltd | Real estate | 2025 |
| AIC Management Ltd | Professional & scientific | 2023 |
| AIC Property Group Limited | Real estate | 2023 |
| AIC Property Holdings Limited | Real estate | 2026 |
| AIL Let's and Stay's Ltd | Real estate | 2025 |
| AIM 4 Limited | Professional & scientific | 1999 |
| AIM4BIRDIES Limited | Wholesale & retail | 2019 |
| Airey & Heaney Limited | Professional & scientific | 2010 |
| Airlane Pneumatics Limited | Manufacturing | 2005 |
| Airsure Holidays Ltd | Administrative & support | 2016 |
| Aivie Properties Limited | Real estate | 2025 |
| AIW QS Solutions Ltd | Professional & scientific | 2026 |
| AJ & D Properties Ltd | Real estate | 2026 |
| AJ Lawrence Logistics Ltd | Transport & logistics | 2024 |
| AJ Logistics Limited | Transport & logistics | 2025 |
| AJ Properties North Ltd | Real estate | 2023 |
| AJ Property Group Investment Ltd | Real estate | 2026 |
| AJ R&P 13 Ltd | Real estate | 2025 |
| Aj's Stores Ltd | Wholesale & retail | 2020 |
| Ajacs NE Ltd | Real estate | 2018 |
| Ajascend Limited | Wholesale & retail | 2026 |
| AJC Renewables Ltd | Manufacturing | 2025 |
| Ajekigbe Health Associates Ltd | Health & social care | 2013 |
| AJET24/7 Ltd | Hospitality | 2023 |
| AJG Accountancy Ltd | Information & communication | 2019 |
| AJH Sunderland Ltd | Wholesale & retail | 2021 |
| AJI Rail Ltd | Professional & scientific | 2024 |
| Ajido Ltd | Wholesale & retail | 2023 |
| Ajlow Consultancy Ltd | Professional & scientific | 2023 |
| AJR Couriers NE Limited | Transport & logistics | 2026 |
| AJS Supplies Limited | Wholesale & retail | 2025 |
| AJW NE Ltd | Hospitality | 2019 |
| AK Maintenance Solutions Ltd | Construction | 2025 |