| Amber Architecture Ltd | Professional & scientific | 2018 |
| AMD Direct Ltd | Wholesale & retail | 2025 |
| Amie & Wish Property Ltd | Real estate | 2022 |
| Amirose London Holdings PLC | Professional & scientific | 2019 |
| Amirose London Limited | Manufacturing | 2009 |
| Amsene Ltd | Extraterritorial | 2023 |
| Amwm Groundworks Ltd | Extraterritorial | 2023 |
| ANC Machinery Ltd | Manufacturing | 2021 |
| Ancient Extracts Ltd | Manufacturing | 2023 |
| Andrew Hyde Building Contractors Limited | Construction | 2018 |
| Angel Cleaners Limited | Construction | 2019 |
| Angel Hill Ltd | Hospitality | 2016 |
| Anglia Air Testing Limited | Construction | 2006 |
| Anglia Consultants Limited | Professional & scientific | 2006 |
| Anglia Door Systems Limited | Manufacturing | 2003 |
| Anglia Forest Limited | Agriculture & fishing | 2020 |
| Anglia Tax & Accountancy Services Limited | Professional & scientific | 2001 |
| Anglia Tax Services Limited | Professional & scientific | 2006 |
| Anglia Truck Services Ltd | Wholesale & retail | 2011 |
| Anglian CUT and Edge Ltd | Manufacturing | 2026 |
| Anglian Digital Group Limited | Information & communication | 2016 |
| Anglian Farming Ltd | Agriculture & fishing | 2010 |
| Anglian Money Advice Services Limited | Administrative & support | 1998 |
| Anglian Truck & Trailer Limited | Manufacturing | 2001 |
| Anglian Warehouses Ltd | Wholesale & retail | 2025 |
| Anglo Panther Power Limited | Energy | 2023 |
| Anglo Ukrainian Review Ltd | Information & communication | 2024 |
| Ani-Motions Limited | Other services | 2018 |
| Anschluss Publishing Limited | Information & communication | 2020 |
| ANSWER4CAR Limited | Wholesale & retail | 2024 |
| Antep Hinckley Ltd | Hospitality | 2023 |
| Antspire Limited | Agriculture & fishing | 1997 |
| Applied Data Consulting Ltd | Professional & scientific | 2026 |
| AQB Engineering Limited | Construction | 2021 |
| Aqcuity Limited | Professional & scientific | 2007 |
| Aquae OPE Services Ltd | Construction | 2019 |
| AR & RR Properties Ltd | Real estate | 2019 |
| Arandess Ltd. | Hospitality | 2016 |
| Arbor Agricultural Services Ltd | Agriculture & fishing | 2013 |
| Arctech Electrical & Renewables Limited | Construction | 2024 |
| Arena Functional Fitness Ltd | Arts & recreation | 2024 |
| Aron Cargo Limited | Transport & logistics | 2019 |
| ARP Trading Limited | Professional & scientific | 2006 |
| Arrowdene Limited | Transport & logistics | 1988 |
| Art Conservation Systems Limited | Administrative & support | 2008 |
| Art..Tech Limited | Construction | 1996 |
| Artemis Cleaning Limited | Administrative & support | 2023 |
| Arturas Services Ltd | Construction | 2017 |
| Artyfakes Action Props Ltd. | Arts & recreation | 2010 |
| AS Carpentry Limited | Manufacturing | 2017 |
| Ashby Estates (Lincoln) Limited | Real estate | 1993 |
| Ashcot Holdings Limited | Financial services | 2021 |
| Ashill Fire Protection Limited | Public administration | 2005 |
| Ashill Lodge Care Limited | Health & social care | 2016 |
| ASK Clay Ltd | Manufacturing | 2025 |
| Aspen Events Ltd | Other services | 2023 |
| Astonpath Limited | Real estate | 2008 |
| Atari Games International Ltd | Information & communication | 2025 |
| Athena Education Support CIC | Education | 2019 |
| Atkin Investments Limited | Real estate | 2014 |
| Atkin Machinery Limited | Wholesale & retail | 2022 |
| Attleborough Investments Ltd | Real estate | 2019 |
| Auctionfresh CIC | Wholesale & retail | 2012 |
| Auditing Consultancy & Training Services Ltd | Education | 2019 |
| Audley Knott Limited | Real estate | 2025 |
| Aurora Intelligence Systems Ltd | Information & communication | 2026 |
| Austin James Ltd | Extraterritorial | 2018 |
| Auto & Storage Gems Ltd | Wholesale & retail | 2025 |
| Auto Custom Performance Limited | Manufacturing | 2017 |
| Auto Xpress Direct Limited | Wholesale & retail | 2025 |
| Autofinish Carsales Ltd | Wholesale & retail | 1995 |
| Avenues&Pathways Ltd | Health & social care | 2022 |
| Axentium Professional Services Ltd | Information & communication | 2025 |
| Axiom Environmental Limited | Water & waste | 2011 |
| Ayaan Rice Limited | Wholesale & retail | 2015 |
| Ayda Private Hire & ALL Trader Ltd | Transport & logistics | 2025 |
| Aygun Delivery Ltd | Transport & logistics | 2021 |
| Aylatrade Ltd | Wholesale & retail | 2023 |
| B & H Laces Limited | Wholesale & retail | 1988 |
| B3N Co Ltd | Real estate | 2021 |
| Baby Toes Preloved Clothes Ltd | Wholesale & retail | 2026 |
| Baker Management Consultancy Ltd | Professional & scientific | 2023 |
| Baldaci Ltd | Hospitality | 2022 |
| Bales Browne Accountancy Services Limited | Professional & scientific | 2006 |
| Baljogi PVT Ltd | Wholesale & retail | 2019 |
| Ballard Engineering Services Ltd | Professional & scientific | 2022 |
| Ballycrystal Limited | Construction | 2023 |
| Baltic Lounge Ltd | Hospitality | 2026 |
| Bane Properties Ltd | Real estate | 2025 |
| Banham Developments Ltd | Administrative & support | 2016 |
| Barkers Equestrian Limited | Wholesale & retail | 2023 |
| Barnscape Developments Limited | Construction | 2014 |
| Barrow 1962 Limited | Extraterritorial | 2014 |
| Bathco Designs Limited | Wholesale & retail | 2021 |
| Battle Stations Ltd | Arts & recreation | 2025 |
| BC Supplies Ltd | Wholesale & retail | 2018 |
| BDS Commercial Services Limited | Construction | 2013 |
| Bearing Supplies Thetford Ltd | Wholesale & retail | 2013 |
| Bedingfeld Arms Limited | Hospitality | 2011 |
| Beez Leisure Limited | Manufacturing | 2014 |