| Arcus Accountants Ltd | Other services | 2019 |
| Arcus Associates Ltd | Professional & scientific | 2004 |
| Arete Legal Limited | Professional & scientific | 2024 |
| Arnold Wills and Company Limited | Manufacturing | 1946 |
| Artificial Grass Direct Ltd. | Wholesale & retail | 2011 |
| Artificial Grass London Limited | Wholesale & retail | 2015 |
| Arts for the Heart of England Ltd | Arts & recreation | 2019 |
| Arvio Ltd | Professional & scientific | 2022 |
| ARW Building & Roofing Contractors Limited | Construction | 2016 |
| ASH Communications Limited | Information & communication | 2022 |
| Ashby Building Consultants Limited | Construction | 2013 |
| Ashdalyte Limited | Transport & logistics | 2009 |
| Ashraful Shikder Limited | Real estate | 2025 |
| Ashwell Court Management Company Limited | Households | 1996 |
| Ashwell Food Ltd | Hospitality | 2026 |
| Aspen House Property Consultants Ltd | Real estate | 2010 |
| Aspire 2 Mobility Ltd | Wholesale & retail | 2021 |
| Aspire Cloud Solutions Limited | Administrative & support | 2016 |
| Assessment Legal Limited | Information & communication | 2017 |
| Astley-Stone Limited | Professional & scientific | 2008 |
| Astral Azure Limited | Professional & scientific | 2013 |
| AT One Limited | Professional & scientific | 2007 |
| ATA Dubh Consulting Limited | Information & communication | 2021 |
| ATT & ALS Limited | Real estate | 2025 |
| Audit Compliance Ltd | Professional & scientific | 2015 |
| Aust Electrical Services Ltd | Construction | 2026 |
| Automate YOU Limited | Information & communication | 2024 |
| Avelia Aesthetics Ltd | Other services | 2026 |
| AX Property Services Limited | Households | 2024 |
| Axiom Consultancy Ltd | Professional & scientific | 2021 |
| B.I. Groundwork Construction Limited | Extraterritorial | 1997 |
| Back 2 Form Limited | Professional & scientific | 2023 |
| Baggy's Coffee Co Ltd | Wholesale & retail | 2024 |
| Bagshaw Engineering & Design Ltd | Professional & scientific | 2024 |
| Bainton Fisheries Limited | Agriculture & fishing | 2009 |
| Balfour Holdings Ltd | Real estate | 2025 |
| Bambeco Solutions Ltd. | Wholesale & retail | 2019 |
| Baptist Bathrooms Ltd | Construction | 2025 |
| Barefoot Flooring Ltd | Wholesale & retail | 2012 |
| Barefoot Franchise Ltd | Wholesale & retail | 2019 |
| Barker Assets Limited | Wholesale & retail | 2014 |
| Barnstone Accountancy & Management Ltd | Professional & scientific | 2005 |
| Barrafina Borough Yards Ltd | Hospitality | 2018 |
| Barrafina International Ltd | Hospitality | 2025 |
| Barrafina Limited | Hospitality | 2006 |
| Barrafina Outside Catering Ltd | Hospitality | 2016 |
| Barre Red Ltd | Professional & scientific | 2021 |
| Barrowden and Wakerley Community Shop Limited | Wholesale & retail | 2006 |
| Baseline Aviation Services Limited | Administrative & support | 2013 |
| Batwine Limited | Wholesale & retail | 2012 |
| Bauwer Group Limited | Construction | 2016 |
| Baxco Associates Limited | Construction | 2018 |
| BBS Fencing Limited | Construction | 2015 |
| Bear & Bump Properties Ltd | Real estate | 2023 |
| Beattie Property Investments Ltd | Real estate | 2022 |
| Beautiful Papers Limited | Administrative & support | 2016 |
| Beaver Inns Limited | Hospitality | 2003 |
| Befit Gymnasium Ltd | Arts & recreation | 2022 |
| Befit Investments Ltd | Real estate | 2025 |
| Belderbos Solicitors Limited | Professional & scientific | 2020 |
| Belest Ltd | Wholesale & retail | 2024 |
| Beljen Ltd | Wholesale & retail | 2025 |
| Bella & ME Ltd | Wholesale & retail | 2026 |
| Belvoir Veterinary Centre Ltd | Professional & scientific | 2020 |
| Benjamin Clark Photography Ltd | Professional & scientific | 2014 |
| BGC Events Limited | Administrative & support | 2009 |
| Bills Bar 2017 Ltd | Hospitality | 2022 |
| Birchleaf Learning Ltd | Education | 2023 |
| Birkland Properties Limited | Real estate | 2019 |
| Birklands Accountancy Ltd | Professional & scientific | 2017 |
| Bitbaboon Limited | Information & communication | 2013 |
| Biznix Ltd | Hospitality | 2020 |
| Black Cube Holdings Ltd | Transport & logistics | 2024 |
| Blck Rain Ltd | Wholesale & retail | 2025 |
| Blitz Apparel Ltd | Wholesale & retail | 2026 |
| Blog the Builder Limited | Construction | 2025 |
| Blue Dragonfly Group Ltd | Administrative & support | 2018 |
| Blue Dragonfly Insights Limited | Professional & scientific | 2021 |
| Blue Sky Wildlife Limited | Administrative & support | 2019 |
| Bluezero Consulting Ltd | Administrative & support | 2018 |
| Boardroom Skateparks Limited | Construction | 2016 |
| BOD Groundworks Limited | Construction | 2016 |
| Boltmere Group Limited | Construction | 2026 |
| Bonnington Associates Limited | Real estate | 1959 |
| Borthwick Holding Ltd | Professional & scientific | 2017 |
| Boss Consultancy Ltd | Professional & scientific | 2005 |
| Botanic Services Ltd | Real estate | 2018 |
| Bower & Hern Limited | Manufacturing | 2005 |
| Bradshaw Taylor Holdings Limited | Financial services | 2018 |
| Braintree Housing Company Limited | Real estate | 2014 |
| Brand Bridge Limited | Wholesale & retail | 2026 |
| Brand Extension Ltd | Professional & scientific | 2012 |
| Brantwood Build and Design (UK) Limited | Construction | 2016 |
| Braunston House Residents Association Limited | Households | 2007 |
| Braunston Road Property Management Company Limited | Households | 2018 |
| Brave Conversations Ltd. | Professional & scientific | 2016 |
| Breathe We'Ve GOT This Ltd | Other services | 2023 |
| Brewmasters @ Rutland Point Limited | Hospitality | 2025 |
| Brian and Charles Film Ltd | Information & communication | 2020 |
| Briarwood Leisure Limited | Hospitality | 2021 |