| Apex Accounting & Tax Solutions Ltd | Professional & scientific | 2025 |
| Apex Financial Advisers Ltd. | Financial services | 2017 |
| Apex Growth Partner Ltd | Professional & scientific | 2024 |
| Apex UK Tax & Accounting Experts Ltd | Professional & scientific | 2025 |
| Apexion Ventures Limited | Professional & scientific | 2024 |
| Appaloosa Management Ltd | Financial services | 2021 |
| Arar Properties Ltd | Real estate | 2025 |
| ARC Design Network Limited | Professional & scientific | 2012 |
| ARC Design Partnership LLP | | 2012 |
| Arcangel Images Limited | Information & communication | 2002 |
| Arch Refurbishment Limited | Construction | 2014 |
| Archgate Investments Ltd | Real estate | 2018 |
| ARG Holdings Limited | Other services | 2022 |
| ARG Insolvency Recoveries Ltd | Financial services | 2022 |
| Ariel Space Ltd | Real estate | 2023 |
| Arise - Shine Your Light CIC | Other services | 2025 |
| Arkin Developments Limited | Construction | 2019 |
| Arlomay Limited | Professional & scientific | 2025 |
| Armarine Shipping Limited | Administrative & support | 1987 |
| Armx Technology and Innovation Ltd | Manufacturing | 2024 |
| Aron Commercial Enterprises Limited | Administrative & support | 2016 |
| Artema Properties Ltd | Real estate | 2003 |
| Artemis Rail Ltd | Construction | 2022 |
| Artgard Limited | Real estate | 2010 |
| Artventures International Limited | Arts & recreation | 2024 |
| Arun Network Solutions Ltd | Information & communication | 2010 |
| Ascension 44 Ltd | Real estate | 2025 |
| Asdk Property Ltd | Real estate | 2024 |
| ASE Store Ltd | Wholesale & retail | 2022 |
| Ashar London Ltd | Manufacturing | 2023 |
| Ashchurch Design & Build Ltd. | Construction | 2001 |
| Ashworld Limited | Other services | 1991 |
| Asset Star Commodities Limited | Construction | 2018 |
| Assetence Limited | Information & communication | 2025 |
| Aston Quantum Ltd | Professional & scientific | 2007 |
| Astute Technical Services Limited | Professional & scientific | 2010 |
| ATM Accounting Services Ltd | Professional & scientific | 2018 |
| Atrium Insight Ltd | Administrative & support | 2016 |
| Attic Blue Limited | Arts & recreation | 2014 |
| ATW Carpentry Ltd | Construction | 2023 |
| Automotive Management Insights Ltd | Professional & scientific | 2017 |
| Automotive-Craft Ltd | Wholesale & retail | 2025 |
| Autovisum Ltd | Information & communication | 2021 |
| AV KAY Limited | Professional & scientific | 2016 |
| Avail Services Ltd | Professional & scientific | 2022 |
| Avanti Cleaning Services Limited | Administrative & support | 2009 |
| Avaug Communications Limited | Information & communication | 2014 |
| Avza Consulting Ltd | Administrative & support | 2013 |
| Away With IT Waste Management Ltd | Water & waste | 2017 |
| Aygrow Consulting Ltd | Information & communication | 2021 |
| Ayyan & Arhaan Brothers Ltd | Real estate | 2025 |
| AZ London (Beauty) Ltd | Other services | 2011 |
| AZ London (Bridal) Ltd | Other services | 2011 |
| AZ London Ltd | Other services | 2011 |
| AZ London Training Academy Ltd | Other services | 2011 |
| Azhar Heating Limited | Construction | 2016 |
| Azooza Ltd | Wholesale & retail | 2018 |
| Azura Travel Limited | Administrative & support | 2002 |
| B88 (London) Ltd | Real estate | 2018 |
| Bababoom Limited | Wholesale & retail | 2009 |
| Babenia Properties Ltd | Real estate | 2024 |
| Back Lane Properties Ltd | Real estate | 2018 |
| Baggymedia Ltd | Information & communication | 2020 |
| Bakery Court Stansted Block Management Limited | Households | 2023 |
| Ballium Limited | Information & communication | 2013 |
| Banks Office Supplies Limited | Wholesale & retail | 2011 |
| Barbs FC Limited | Hospitality | 2023 |
| Barclay Developments Limited | Manufacturing | 2007 |
| Baronshield Finance Limited | Other services | 2003 |
| Barrett Education Limited | Education | 2026 |
| Barretts Law Limited | Professional & scientific | 2022 |
| Barrington Lettings Limited | Real estate | 2007 |
| Barrow Maintenance Services Ltd | Construction | 2021 |
| Battledean Limited | Professional & scientific | 2000 |
| Baystock Limited | Administrative & support | 2009 |
| Bbrb Properties Limited | Real estate | 2017 |
| Bdef Limited | Professional & scientific | 2006 |
| Beales Services Limited | Construction | 2018 |
| Beau Amos Ltd | Construction | 2025 |
| Beau Gray Scaffolding Ltd | Construction | 2015 |
| BEE Services UK Ltd | Administrative & support | 1984 |
| Belgilux Properties Limited | Real estate | 2001 |
| Belgravia Roofing Limited | Construction | 2025 |
| Bella Capelli Essex Limited | Other services | 2026 |
| Belltech Consultants Limited | Information & communication | 1992 |
| Bernice Park Holdings Ltd | Financial services | 2025 |
| Bertilly Ltd | Administrative & support | 2026 |
| Bespoke Bookkeeping Ltd | Professional & scientific | 2016 |
| Bespoke Lofts Ltd | Construction | 2005 |
| Bespoke London Projects Limited | Construction | 2024 |
| Betterment Wealth Limited | Professional & scientific | 2007 |
| Bevvyclub Limited | Information & communication | 2025 |
| BEX Builders Ltd | Construction | 2009 |
| BG Cleaning Solutions Limited | Administrative & support | 2015 |
| BH Construction Projects Ltd | Construction | 2016 |
| BH Lines Ltd | Construction | 2024 |
| Big 5 Sports Management Limited | Professional & scientific | 2017 |
| Bijoux Hub Limited | Wholesale & retail | 2024 |
| Biker Limited | Professional & scientific | 2022 |
| Biobright Ltd | Agriculture & fishing | 2021 |