| Apex Roaming Management Ltd | Information & communication | 2014 |
| Apex Roofing Essex Limited | Construction | 2025 |
| Apex SQR UK Limited | Hospitality | 2025 |
| Aphisara Ltd | Hospitality | 2013 |
| Aphisara Restaurant Limited | Hospitality | 2017 |
| Applegreen Contracts Limited | Professional & scientific | 1986 |
| Apricotxpress Ltd | Professional & scientific | 2024 |
| April's Helping Hands Ltd | Administrative & support | 2026 |
| Aqua Vera Limited | Manufacturing | 2026 |
| Aquajet Power Clean Limited | Administrative & support | 2014 |
| Aqualuna Media Limited | Administrative & support | 2008 |
| Aquaria Construction & Wellness Ltd | Construction | 2025 |
| Araz Fish Bar Ltd | Hospitality | 2018 |
| Area B BW Limited | Households | 2014 |
| Argo Bullies Ltd | Agriculture & fishing | 2024 |
| Arinola Limited | Health & social care | 2022 |
| Aris Financial Limited | Extraterritorial | 2016 |
| ARK Cloud Ltd | Information & communication | 2017 |
| ARL Utility Solutions Ltd | Construction | 2025 |
| Arlo Consultancy Services Ltd | Professional & scientific | 2024 |
| Arnrus Limited | Hospitality | 2004 |
| Arrow Facilities Management Ltd | Administrative & support | 2022 |
| Arrowouter Limited | Wholesale & retail | 1987 |
| Artha Quest Ltd | Professional & scientific | 2025 |
| Ashanti Curls Limited | Manufacturing | 2019 |
| Ashe Consultancy Limited | Administrative & support | 2002 |
| Ashes Corner Management Limited | Households | 2013 |
| Ashoka & Bimal DEY Ltd | Other services | 2020 |
| Aspire DTN Ltd | Administrative & support | 2024 |
| Aspire East Anglia Limited | Construction | 2014 |
| Aspire Roofing Services Limited | Construction | 2018 |
| Aspire Scaffolding Limited | Construction | 2021 |
| Aspire Transport Limited | Transport & logistics | 2023 |
| Associated Plumbing Limited | Construction | 1998 |
| Aston Scaffolding Solutions Ltd | Construction | 2020 |
| Atlantis Office Group Limited | Financial services | 2024 |
| Attraction Solutions Ltd | Arts & recreation | 2025 |
| Audiovisualinstalls.Co.Uk Ltd | Households | 2011 |
| Aura Developments Limited | Real estate | 2019 |
| Aurexion Capitals Ltd | Professional & scientific | 2026 |
| Aurum Essex Ltd | Financial services | 2025 |
| Aurum Source Advisory Ltd | Professional & scientific | 2026 |
| Autism Support Centre CIC | Public administration | 2026 |
| Automotive Services Witham Ltd | Wholesale & retail | 2026 |
| Autumn Care Homes Ltd | Health & social care | 2013 |
| Avanti Design Ltd | Professional & scientific | 2024 |
| Avon Internet Services Limited | Professional & scientific | 1995 |
| Avondale Road (Gorleston) Management Limited | Real estate | 2023 |
| Axis Contracts Ltd | Professional & scientific | 2015 |
| Azack Limited | Transport & logistics | 2019 |
| Azsure Ltd | Information & communication | 2025 |
| B B Harrison Limited | Professional & scientific | 2013 |
| B R Watts Ltd | Professional & scientific | 2019 |
| B W C Limited | Construction | 2007 |
| Baba RE International Limited | Real estate | 2020 |
| Baba RE Ltd | Financial services | 2017 |
| Babua Limited | Real estate | 2020 |
| BAC Swimming Academy Ltd | Education | 2021 |
| Badgefleet Limited | Construction | 1990 |
| Balanced FC Coaching Ltd | Education | 2021 |
| Balanced Football Club C.I.C. | Arts & recreation | 2025 |
| Ballers Cleaning Services Ltd | Administrative & support | 2022 |
| Balmoral Cleaning Services Ltd | Administrative & support | 2025 |
| Bamora Ltd | Extraterritorial | 2024 |
| Band Theft Audio Ltd. | Arts & recreation | 2018 |
| Banson Maintenance Limited | Households | 2021 |
| Bantock Way Management Co Limited | Households | 2024 |
| Banyard Recruitment Limited | Administrative & support | 2025 |
| Barakha Enterprise Ltd | Hospitality | 2019 |
| Barkobe Projects Ltd | Information & communication | 2015 |
| Barley Taverns Ltd | Hospitality | 2001 |
| Basildon Second Hand Retailers LLP | | 2013 |
| Baverstocks AI Limited | Extraterritorial | 2023 |
| Baverstocks Holdings Limited | Professional & scientific | 1999 |
| Baverstocks Limited | Professional & scientific | 1986 |
| Baxter Architectural Hardware Ltd | Manufacturing | 2020 |
| BB Amplification Ltd | Manufacturing | 2011 |
| BCS Services (London) Ltd. | Administrative & support | 1997 |
| BCS Services Ltd. | Administrative & support | 1971 |
| Bea's Balloons & Occasions Ltd. | Wholesale & retail | 2017 |
| Bealiam Ltd | Professional & scientific | 2021 |
| Bealiam Property Management Ltd | Real estate | 2018 |
| Bearing and Engineering Solutions Ltd | Professional & scientific | 2016 |
| Beaumaris Estates Ltd | Real estate | 2020 |
| Bedfordshire Internet Services Limited | Professional & scientific | 1995 |
| Belleview Healthcare Limited | Health & social care | 2022 |
| Bels Beauty Ltd | Other services | 2023 |
| Benchmark Consulting International (Europe) Ltd | Professional & scientific | 2017 |
| Bentley Stanton Partners Limited | Professional & scientific | 2009 |
| Berkshire Internet Services Limited | Professional & scientific | 1995 |
| Berso Ltd | Other services | 2025 |
| Bespoke Audiology Services Limited | Wholesale & retail | 2025 |
| Bespoke Music Management Ltd. | Information & communication | 1997 |
| Beta Pharmaceuticals Limited | Wholesale & retail | 2003 |
| Betula Ascot Limited | Real estate | 2012 |
| BEV IQ Ltd | Extraterritorial | 2021 |
| Beverex Limited | Wholesale & retail | 2019 |
| Bevgardien Ltd | Administrative & support | 2025 |
| Beyond Numbers Consulting Ltd | Professional & scientific | 2025 |
| BHF Developments Limited | Extraterritorial | 2018 |