| Amber Rose Contracts Ltd | Construction | 2024 |
| Ambercliff Ltd | Real estate | 2024 |
| Ambers Legacy (NE) Limited | Other services | 2022 |
| Ambialet Ltd | Water & waste | 2010 |
| Amborne Limited | Wholesale & retail | 2018 |
| Ambrose Crest Limited | Health & social care | 2026 |
| Ambuline Limited | Transport & logistics | 1993 |
| AMC Cars North East Limited | Wholesale & retail | 2026 |
| Amed Barber Ltd | Other services | 2020 |
| Amee Delivery Service Limited | Transport & logistics | 2025 |
| Ameer and Ameera Ventures Ltd | Wholesale & retail | 2025 |
| American Candi Evapo Ltd | Wholesale & retail | 2026 |
| Amethyst Cleaning Service Ltd | Administrative & support | 2023 |
| Amhrq Limited | Wholesale & retail | 2025 |
| Amigo Roker Ltd | Hospitality | 2022 |
| Amir and ALI Limited | Other services | 2022 |
| Amir Persian Bite Ltd | Hospitality | 2023 |
| Amisphere Ltd | Information & communication | 2025 |
| Amissah Ltd | Other services | 2024 |
| Amiviw Ltd | Other services | 2025 |
| AMK Painting & Decorating Ltd | Construction | 2025 |
| AML Property Developments Limited | Construction | 2024 |
| AML Property North East Ltd | Real estate | 2024 |
| Among the Stars Ltd | Education | 2025 |
| Ampark Properties Ltd | Real estate | 2026 |
| AMS (NE) Ltd | Construction | 2014 |
| AMS Publishing Ltd | Information & communication | 2019 |
| AMZ Pharma Ltd | Administrative & support | 2023 |
| Anakins Property Management Ltd | Real estate | 2025 |
| Anakins Property Solutions Ltd | Real estate | 2025 |
| Analutos Ltd | Health & social care | 2010 |
| Ananas Networks Limited | Information & communication | 2024 |
| Anatolian Barbers Ltd | Other services | 2022 |
| Anaya Maison Ltd | Real estate | 2024 |
| ANC Recycling Ltd | Water & waste | 2024 |
| Anchor & Wright Limited | Education | 2025 |
| Ancurley Ltd | Administrative & support | 2012 |
| Anderson Brothers (Shopfitters) Limited | Professional & scientific | 1958 |
| Anderson Estates (NE) Ltd | Real estate | 2023 |
| Andova Distribution Limited | Wholesale & retail | 2025 |
| Andrea Birrell Ltd | Wholesale & retail | 2025 |
| Andrew Bell Specialist Access Ltd | Construction | 2025 |
| Andrew Lang Limited | Extraterritorial | 2023 |
| Andrew P Miller Ltd | Construction | 2021 |
| Andy Fairless Authorising Engineering Services Ltd | Professional & scientific | 2025 |
| ANE Ltd | Professional & scientific | 2024 |
| Aneevo Ltd | Financial services | 2023 |
| Angela Cuisine Ltd | Hospitality | 2026 |
| Angela Wake Limited | Wholesale & retail | 2025 |
| Angela's ARK Limited | Education | 2021 |
| Angelic Food Restaurant Ltd | Hospitality | 2025 |
| Angle Property North East Ltd | Real estate | 2023 |
| Anic Investment Ltd | Construction | 2021 |
| Animal Krackers Limited | Wholesale & retail | 2003 |
| Anna Rhodes Fitness Limited | Health & social care | 2020 |
| Annie's Crafty Emporium (Ace) Ltd | Wholesale & retail | 2025 |
| Annie's Crafty Emporium Community Interest Company | Wholesale & retail | 2025 |
| Anoksa Trading Company Limited | Wholesale & retail | 2012 |
| Anth Stubbs Coaching Ltd | Other services | 2023 |
| Anthony Carter Compliance Limited | Professional & scientific | 2025 |
| Anthony Haigh Limited | Professional & scientific | 1968 |
| Anthony Iley Electrical Contractors Limited | Construction | 2023 |
| Anthony James Lettings NE Limited | Real estate | 2025 |
| Anthony James Property Ltd | Real estate | 2016 |
| Anthony Stephen Laybourne Ltd | Extraterritorial | 2025 |
| Antshake Ltd | Information & communication | 2007 |
| ANU Property Investment Ltd | Real estate | 2025 |
| ANY Key Games Ltd | Information & communication | 2024 |
| Aoal Limited | Health & social care | 2025 |
| AP Fencing Services Limited | Construction | 2025 |
| AP Payroll Services Limited | Wholesale & retail | 2019 |
| APA Offshore Services Ltd | Construction | 2024 |
| APD Cleadon Limited | Professional & scientific | 2015 |
| Apex Educational Hub Ltd | Education | 2026 |
| Apex Integrity Services Ltd | Manufacturing | 2026 |
| Apex Performance Holding Limited | Administrative & support | 2023 |
| Apex Resin Decor Ltd | Construction | 2024 |
| Apex Verdict Electrical Installation and Building Services Limited | Construction | 2025 |
| APG Garden Services Ltd | Administrative & support | 2025 |
| APG Logistics & Engineering Ltd | Transport & logistics | 2024 |
| APJ Drainage Ltd | Water & waste | 2025 |
| Apmm Properties Ltd | Real estate | 2022 |
| APO 2018 Ltd | Hospitality | 2026 |
| Applebeez Property Clearance Ltd | Transport & logistics | 2024 |
| Applied Monitoring Ltd | Information & communication | 2018 |
| Apprentice Films Ltd | Information & communication | 2025 |
| Approved Mortgage Solutions Limited | Financial services | 2007 |
| APS Services (NE) Ltd | Other services | 2026 |
| Apsc Electrical Ltd | Construction | 2014 |
| APT Online Traders Limited | Wholesale & retail | 2019 |
| AQ Electrical and Fire Services Ltd | Construction | 2026 |
| AQI Barber Ltd | Other services | 2024 |
| Aquilo Holdings Ltd | Financial services | 2023 |
| Aquinox Contracts Ltd | Construction | 2016 |
| AQX Property Ltd | Real estate | 2026 |
| AR Controls Holdings Limited | Financial services | 2024 |
| AR Controls Ltd | Manufacturing | 2013 |
| Arans Retail Limited | Wholesale & retail | 2022 |
| ARC Associates (NE) Limited | Professional & scientific | 2011 |
| ARC Holdings NE Ltd | Real estate | 2023 |