| Ashington Community Football Club Limited | Arts & recreation | 2008 |
| Ashington Healthcare Limited | Wholesale & retail | 2023 |
| Ashington Launderette Ltd | Other services | 2026 |
| Ashington Learning Partnership Trust | Education | 2007 |
| Ashington Leisure Partnership | Arts & recreation | 2011 |
| Ashington Lintonville Limited | Wholesale & retail | 2024 |
| Ashington Minors Ltd | Health & social care | 2002 |
| Ashington Pizza Ltd | Hospitality | 2023 |
| Ashington Removals & Storage Centre Limited | Transport & logistics | 2012 |
| Ashington Sale Rooms Ltd | Wholesale & retail | 2012 |
| Ashington Service Centre Limited | Wholesale & retail | 2007 |
| Ashington Timber & Joinery Ltd | Wholesale & retail | 2019 |
| Ashington Van Centre Limited | Wholesale & retail | 2002 |
| Asifa Spice Ltd | Hospitality | 2018 |
| Asotom Healthcare Limited | Health & social care | 2023 |
| Assetwatch Ltd | Administrative & support | 2011 |
| Athens Greek Food Limited | Hospitality | 2019 |
| Atom Housing Ltd | Real estate | 2020 |
| Ausk Services Ltd | Administrative & support | 2025 |
| Avalon Engineering Services Ltd | Professional & scientific | 2024 |
| Avant Calcio Ltd | Professional & scientific | 2023 |
| Avis Auto Care Ltd | Wholesale & retail | 2025 |
| AXE Lyrical Ltd | Arts & recreation | 2023 |
| Ayan Fish N Chips Ltd | Hospitality | 2026 |
| Aztech Site Services Ltd | Professional & scientific | 2024 |
| B a Plant Hire Ltd | Administrative & support | 2016 |
| B Storey Bolting Services Limited | Construction | 2023 |
| B&D Auto Solutions Ltd | Wholesale & retail | 2025 |
| Bagci Properties Ltd | Real estate | 2026 |
| Balkan Pizza Ltd | Hospitality | 2026 |
| Ballsy Media Limited | Information & communication | 2014 |
| Bandits Barbershop Ltd | Other services | 2020 |
| Bean and Bite Limited | Wholesale & retail | 2025 |
| Beauty and the Beast Tattoo Limited | Other services | 2021 |
| Beauty at Your Fingertips Ltd | Other services | 2024 |
| Beauty by Hollym Limited | Other services | 2025 |
| Becwood Lodges Ltd | Hospitality | 2025 |
| Bede Films Limited | Information & communication | 2006 |
| Bedouin Communications Limited | Construction | 2009 |
| Being Woman | Education | 2018 |
| Bell Integrity Services Ltd | Other services | 2019 |
| Bellachowuk Limited | Wholesale & retail | 2026 |
| Bellissimo Pizza & Grill Ltd | Hospitality | 2019 |
| Bentley Brown & Co Ltd | Professional & scientific | 2005 |
| Bernicia Homes Limited | Real estate | 2015 |
| Bernicia Housing Limited | Real estate | 1997 |
| Best Options Agency Limited | Health & social care | 2019 |
| Bishops of Sussex Limited | Construction | 2017 |
| Bitstor Ltd | Information & communication | 2025 |
| Bjdl Limited | Professional & scientific | 2020 |
| Black Knight Limited | Real estate | 1992 |
| Blackarc Group Ltd | Financial services | 2024 |
| Blnk MFG Ltd | Manufacturing | 2023 |
| Blossoming Beauty Ltd | Other services | 2024 |
| Blyth Sales Ltd | Real estate | 2018 |
| Bobby G Properties Limited | Real estate | 2025 |
| Body Repairs NE Ltd | Wholesale & retail | 2025 |
| Bodycraft Northumberland Limited | Wholesale & retail | 2022 |
| Bookmakers Technology Consortium Limited | Information & communication | 2008 |
| Border Vending North East Ltd | Hospitality | 2017 |
| Bordershore Developments Ltd | Construction | 2023 |
| Bordershore Investments Ltd | Real estate | 2023 |
| Bordershore Ltd | Financial services | 2023 |
| Bournehouse Automation Systems Limited | Professional & scientific | 2021 |
| Boyd Technologies Ashington UK Limited | Manufacturing | 1998 |
| BR Accountancy Services Limited | Professional & scientific | 2023 |
| BR Sales Ltd | Wholesale & retail | 2025 |
| Bradbury Estates Ltd | Real estate | 2022 |
| Brenkley Motorhomes Limited | Administrative & support | 2020 |
| Brightside Adult Services Limited | Health & social care | 2016 |
| Brightside Respite Services Limited | Health & social care | 2021 |
| Brightside Supported Living Services Limited | Health & social care | 2020 |
| Brindale Limited | Manufacturing | 2004 |
| Brinkburn Garages Limited | Wholesale & retail | 2025 |
| Brionyscantlebury Limited | Information & communication | 2026 |
| Brownbranch North East Limited | Hospitality | 2018 |
| Brownsman Limited | Information & communication | 2008 |
| BRS Offshore Ltd | Manufacturing | 2025 |
| Brynden Evans Ltd | Professional & scientific | 2024 |
| BSG Onsite Support Ltd | Construction | 2022 |
| Bskg Ltd | Real estate | 2018 |
| Buffet Ninja Ltd | Hospitality | 2016 |
| Butters Cole Developments NE Ltd | Real estate | 2020 |
| Buys Direct Ltd | Professional & scientific | 2021 |
| BVT 917 Limited | Other services | 2019 |
| C W Electrical (NE) Ltd | Construction | 2020 |
| C&S Retreats Ltd | Hospitality | 2021 |
| CA Mendoza Ascent Ltd | Administrative & support | 2024 |
| Cabin Escapes Limited | Hospitality | 2020 |
| CAL Lettings Ltd | Real estate | 2020 |
| Calbro Bathrooms Ltd | Construction | 2022 |
| Car Cleaning-Uk Ltd | Wholesale & retail | 2019 |
| Carbank Limited | Transport & logistics | 1986 |
| Carers Northumberland Limited | Health & social care | 2007 |
| Castle Island Cars and Commercials Ltd | Wholesale & retail | 2023 |
| Castle Island Service & Repair Centre Ltd | Wholesale & retail | 2024 |
| Cavendish Home Care Ltd | Public administration | 2019 |
| Cavendish Kitchens & Bedrooms Limited | Wholesale & retail | 1990 |
| CB Mechanical Solutions Ltd | Professional & scientific | 2025 |
| CC Caravans Ltd | Manufacturing | 2021 |