| 1ST Carpentry Portsmouth Ltd | Construction | 2025 |
| 24 Capital Limited | Professional & scientific | 2009 |
| 3 Core Electrical Limited | Construction | 2010 |
| 3 D Contract Services Limited | Administrative & support | 2005 |
| 3 D Transport (Berwick) Ltd | Transport & logistics | 2010 |
| 33 Beauchamp Road Management Company Limited | Real estate | 1987 |
| 41 Fernshaw Road Limited | Hospitality | 1995 |
| 4P Property Services Limited | Other services | 2016 |
| 76 Chaucer Road Limited | Real estate | 2001 |
| 7AM Retail Limited | Wholesale & retail | 2014 |
| A & H Farming LLP | | 2006 |
| A & J Sheldrake Ltd | Agriculture & fishing | 2019 |
| A & J Webster Eggs Limited | Agriculture & fishing | 2017 |
| A Note From Northumberland Ltd | Wholesale & retail | 2023 |
| A. Carmichael (Farmers) Limited | Agriculture & fishing | 1961 |
| A.O.Barber Limited | Agriculture & fishing | 1971 |
| A1 Eco Solutions Ltd | Construction | 2013 |
| Aaron Nicholl Joinery Limited | Manufacturing | 2020 |
| Action Alley Ltd | Wholesale & retail | 2014 |
| Addison-Ross Limited | Administrative & support | 2008 |
| Aequalis Partners Limited | Professional & scientific | 2016 |
| Agni Advisers Ltd | Professional & scientific | 2026 |
| AI Talent Sourcing Partner Limited | Administrative & support | 2025 |
| Ainscough Farm Company | Professional & scientific | 1998 |
| AJS Joiners Limited | Manufacturing | 2025 |
| Alarm Smart Limited | Construction | 2019 |
| Albury House Residential Care Ltd | Health & social care | 2025 |
| Alex Dale Ltd | Agriculture & fishing | 2008 |
| Alice&Thomas Homes Ltd | Real estate | 2022 |
| Allan Brothers Limited | Manufacturing | 2006 |
| Amawell Limited | Construction | 2004 |
| American Nails & Spa 33 Ltd | Other services | 2024 |
| AMJ Restaurants Ltd | Hospitality | 2018 |
| Amore Ristorante Ltd | Hospitality | 2023 |
| Amped Berwick CIC | Education | 2025 |
| AMS Industrial Cleaning Ltd | Administrative & support | 2023 |
| Anco International Limited | Professional & scientific | 1987 |
| Ancroft Country Park Limited | Hospitality | 2023 |
| Andrew Robinson (Farms) Limited | Agriculture & fishing | 1972 |
| Anglo Hillwood Limited | Financial services | 2016 |
| Anglo Macscott Limited | Professional & scientific | 2014 |
| Angusfield Care Limited | Health & social care | 2024 |
| AS Good AS IT Gets Berwick Limited | Hospitality | 2019 |
| AS Good AS IT Gets Cocktails Limited | Hospitality | 2024 |
| Assured Finance Today Ltd | Information & communication | 2013 |
| Assurepoint Solutions Ltd | Administrative & support | 2026 |
| Atlas Change Limited | Professional & scientific | 2014 |
| Auchenglen Properties Limited | Real estate | 1987 |
| Autogether Ltd | Information & communication | 2026 |
| Barbour ALL Terrain Tracking Ltd | Manufacturing | 2000 |
| Barmoor Castle Country Park Limited | Hospitality | 2003 |
| Barmoor Holdings Limited | Financial services | 2023 |
| Baron DE Muschamp Ltd | Wholesale & retail | 2022 |
| Bastion Global Investments Limited | Real estate | 2022 |
| BDS Rope-Access Ltd | Construction | 2026 |
| Beacon Hill Leisure Limited | Arts & recreation | 2005 |
| Beadnell Hotels Limited | Hospitality | 1952 |
| Beal Farm Limited | Agriculture & fishing | 2012 |
| Bear Motorsports Ltd | Professional & scientific | 2020 |
| Beatshield Ltd | Wholesale & retail | 2024 |
| Beaumont Associates (Northumberland) Ltd. | Administrative & support | 2007 |
| BEN Douglas Fencing Ltd | Wholesale & retail | 2026 |
| Benarty View Care Limited | Health & social care | 2024 |
| Bennett Agronomy Ltd | Agriculture & fishing | 2010 |
| Berryburn Farming Company Limited | Financial services | 1964 |
| Berwick & District Rugby Football Foundation | Arts & recreation | 2004 |
| Berwick Contemplative Arts CIC | Education | 2024 |
| Berwick Core Ltd | Energy | 2008 |
| Berwick Film and Media Arts Festival | Arts & recreation | 2005 |
| Berwick Geotechnical Ltd | Construction | 2022 |
| Berwick Homes Limited | Real estate | 2025 |
| Berwick Industrial Developments Limited | Real estate | 2000 |
| Berwick Pubs Limited | Hospitality | 2018 |
| Berwick Rugby Football Club (Trading) Limited | Arts & recreation | 2016 |
| Berwick Rugby Football Club Limited | Arts & recreation | 2009 |
| Berwick Town Team Ltd | Public administration | 2013 |
| Black FOX Metalcraft Ltd | Manufacturing | 2012 |
| Bloomin Borders LP | | 2021 |
| Blue Chip Wood Fuels Ltd | Agriculture & fishing | 2023 |
| Bookless Motors Limited | Wholesale & retail | 1957 |
| Border Airtightness Testing Ltd | Professional & scientific | 2026 |
| Border Links Limited | Education | 2006 |
| Borderline Roofing & Building Ltd | Construction | 2023 |
| Borderline Tattoo Collective Ltd | Other services | 2015 |
| Borders Properties Ltd | Real estate | 2025 |
| BOY Enzo Fishing Ltd | Agriculture & fishing | 2021 |
| Brada Limited | Hospitality | 2021 |
| Brada Quarry Limited | Construction | 2006 |
| Braeview Escapes Limited | Administrative & support | 2018 |
| Bragg Group Ltd | Financial services | 2015 |
| Braidwood Properties Limited | Real estate | 1985 |
| Brandwell GB Trading Limited | Wholesale & retail | 2018 |
| Bricklaying Technologies Limited | Manufacturing | 2024 |
| Bridge Court Management (Berwick) Limited | Hospitality | 1988 |
| Bright Star FIC | Administrative & support | 2026 |
| Bright Star Holding Company 1 | Administrative & support | 2026 |
| Bright Star Holding Company 2 | Administrative & support | 2026 |
| Bryson Electrical Ltd | Construction | 2016 |
| Burton Hall Farm Ltd | Agriculture & fishing | 1988 |
| Buston Farms Limited | Administrative & support | 1985 |