| Apollo School of Motoring Ltd | Education | 2018 |
| Apollo Serbia (UK) Limited | Financial services | 2023 |
| Apoo Ltd | Wholesale & retail | 2025 |
| Apparo LC Ltd | Construction | 2012 |
| Appealing Care Services Limited | Administrative & support | 2016 |
| Apperley Assets Limited | Real estate | 2018 |
| Apperley Holdco Limited | Financial services | 2026 |
| Appernal Limited | Real estate | 1976 |
| Appetite Republic CIC | Education | 2014 |
| Apple PIP Properties Limited | Real estate | 2023 |
| Apple Repairs Newcastle Limited | Information & communication | 2024 |
| Applebuy Mortgages Limited | Financial services | 2017 |
| Appleby Dance Company Ltd | Arts & recreation | 2021 |
| Appleby Management Services Ltd | Professional & scientific | 2011 |
| Appledore DHM Limited | Real estate | 2017 |
| Applegarth Healthcare Limited | Health & social care | 2016 |
| Applied Electrical Services Limited | Construction | 2003 |
| Applied Infrastructure Services Ltd | Professional & scientific | 2022 |
| Apply Mobile Limited | Information & communication | 2011 |
| Appro Solutions Ltd | Professional & scientific | 2020 |
| Apps Total GT Ltd | Information & communication | 2026 |
| Apropos IT Solutions Limited | Information & communication | 1997 |
| APS Hospitality North East Limited | Hospitality | 2019 |
| Apsay Engineering Ltd | Professional & scientific | 2023 |
| Apsay Group Ltd | Other services | 2025 |
| Apsay International Trading Ltd | Wholesale & retail | 2025 |
| Apsay Ltd | Administrative & support | 2022 |
| Apsay Properties Ltd | Real estate | 2025 |
| Aptus Fit OUT Limited | Construction | 2022 |
| APW (NE) Limited | Wholesale & retail | 2023 |
| Aqibbabar Ltd | Wholesale & retail | 2023 |
| Aqsa Pharm Ltd | Health & social care | 2025 |
| Aqua Accounting Ltd | Professional & scientific | 2011 |
| Aqua ARC Ltd | Professional & scientific | 2020 |
| Aquajet Drain Cleaning Limited | Water & waste | 2001 |
| Aqualand the Land of Aqua-Holics Ltd | Agriculture & fishing | 2012 |
| Aquanav Ltd | Professional & scientific | 2020 |
| Aquapea Ltd | Professional & scientific | 2020 |
| Aquaschool Ltd | Education | 2020 |
| Aquaseal Facilities Limited | Other services | 2023 |
| Aquaseal Group Limited | Financial services | 2023 |
| Aquaseal Rubber Limited | Manufacturing | 1992 |
| Aquaseeka Ltd | Professional & scientific | 2020 |
| Aquatran House Ltd | Real estate | 2016 |
| Aquilonaris Ltd | Wholesale & retail | 2021 |
| AR Design Consulting Limited | Administrative & support | 2017 |
| AR Kitchens and Bedrooms Ltd | Wholesale & retail | 2019 |
| AR Property Rental Ltd | Real estate | 2021 |
| AR Recruitment Services Ltd | Administrative & support | 2023 |
| Arabella & Co. Atelier Ltd | Professional & scientific | 2026 |
| Arafat (NE) Ltd | Hospitality | 2017 |
| Aras Tailoring Limited | Manufacturing | 2024 |
| Arasaka Ltd | Wholesale & retail | 2022 |
| ARB Builders Limited | Construction | 2021 |
| ARB Hire Newcastle Limited | Administrative & support | 2023 |
| Arba Recovery Ltd | Transport & logistics | 2024 |
| Arbaaz Property Managements Ltd | Real estate | 2021 |
| Arbeia Energy Limited | Administrative & support | 2021 |
| Arbeia House RTM Company Limited | Real estate | 2012 |
| Arber Solutions Ltd | Real estate | 2022 |
| Arbor Software Ltd | Information & communication | 2024 |
| Arbscape Home & Garden Ltd | Other services | 2022 |
| Arbscape NE Ltd | Administrative & support | 2025 |
| ARC Finance Limited | Professional & scientific | 2022 |
| ARC Financial Ltd | Professional & scientific | 2015 |
| ARC Investment Services Limited | Financial services | 2019 |
| ARC Sports and Gaming Limited | Professional & scientific | 2025 |
| ARC Units and Yards Ltd | Real estate | 2025 |
| ARC Virtual Solutions Ltd | Professional & scientific | 2022 |
| ARC Windows & Doors Ltd | Manufacturing | 2025 |
| ARC Yards Ltd | Construction | 2025 |
| Arcane FOX Limited | Wholesale & retail | 2025 |
| Arch Electrical North East Ltd | Construction | 2023 |
| Arch News NCL Limited | Wholesale & retail | 2021 |
| ARCH2 Development Limited | Real estate | 2016 |
| Archer Marketing Limited | Professional & scientific | 2025 |
| Archer Media UK Ltd | Professional & scientific | 2010 |
| Archi Pixel Limited | Information & communication | 2026 |
| Archisana Ltd | Professional & scientific | 2011 |
| Architecture Group (UK) Ltd | Professional & scientific | 2022 |
| Archive Anonymous Ltd | Wholesale & retail | 2026 |
| Archrise Holdings Limited | Financial services | 2020 |
| Arcmilano Ltd | Manufacturing | 2026 |
| Arcog Engineering Company Limited | Professional & scientific | 2017 |
| Arcos Education Limited | Other services | 2016 |
| Arcot Estate (Cramlington) Management Company Limited | Households | 2022 |
| Arctic Circle Design Ltd | Professional & scientific | 2023 |
| Arctic Wolf Networks UK Ltd | Professional & scientific | 2020 |
| Arcus Immersive Ltd | Information & communication | 2020 |
| Arda Cleaning Limited | Administrative & support | 2020 |
| Ardabili Limited | Health & social care | 2025 |
| Ardelle Ltd | Real estate | 2025 |
| Arden Healthcare Group Limited | Financial services | 2024 |
| Ardos Barbers Sunderland Ltd | Other services | 2023 |
| Area 10 Limited | Other services | 2015 |
| Areca Homes UK Limited | Real estate | 2025 |
| Aref Ltd | Other services | 2021 |
| Arena 55 Limited | Construction | 2019 |
| Arena Car Valeting Ltd | Other services | 2025 |
| Arena Games Holdings Ltd | Arts & recreation | 2025 |