| Awway Limited | Construction | 2015 |
| Axel Connect Ltd | Transport & logistics | 2015 |
| Aximor Ltd | Construction | 2015 |
| Axis & Oak Ltd | Real estate | 2026 |
| Axis Vector Construction Ltd | Construction | 2023 |
| Axis Vector Design Ltd | Professional & scientific | 2015 |
| Axis Vector Ltd | Construction | 2025 |
| Axolotl IT Services Ltd | Information & communication | 2020 |
| Ayelectrical Ltd | Manufacturing | 2026 |
| Ayrus Ltd | Health & social care | 2017 |
| Aysaf Ltd | Wholesale & retail | 2026 |
| Ayyaippa Decor Limited | Administrative & support | 2020 |
| AYZ Works Limited | Transport & logistics | 2024 |
| AZ Chauffeuring Ltd | Transport & logistics | 2026 |
| Azed Associates Limited | Professional & scientific | 2007 |
| Azed Foundation International Limited | Other services | 2007 |
| Azed Investments Limited | Real estate | 2008 |
| AZK Bros Limited | Real estate | 2018 |
| AZM Enterprises Limited | Health & social care | 2011 |
| AZM Property Solutions Ltd | Real estate | 2019 |
| Azteca Tooting Limited | Hospitality | 2019 |
| B & K Installation Ltd | Construction | 2021 |
| B M Minimart Limited | Wholesale & retail | 2023 |
| B P & Sons Transport Ltd | Transport & logistics | 2009 |
| B Tech Construction Ltd | Construction | 2026 |
| B&D Scaffolding Ltd | Construction | 2023 |
| B-Mitrev Ltd | Construction | 2022 |
| B.I.Engi Ltd | Construction | 2018 |
| BA Enterprises Europe Ltd | Financial services | 2001 |
| BA Management & Accountancy Services Ltd | Mining & quarrying | 2020 |
| BA UK Service Ltd | Construction | 2021 |
| Baba D Cleaning Services Ltd | Administrative & support | 2024 |
| Babal Wholesale Limited | Wholesale & retail | 2023 |
| Babastar Construction Ltd | Other services | 2017 |
| Babington Close Ltd | Hospitality | 2018 |
| Back in Shape Limited | Health & social care | 2010 |
| Baddest Brixton CIC | Education | 2024 |
| Badger Social Homes Ltd | Construction | 2025 |
| BAG a Builder Ltd | Information & communication | 2015 |
| Bages Consult Ltd | Information & communication | 2013 |
| Bagi Landscaping Ltd | Construction | 2024 |
| Bajwa Steel Limited | Manufacturing | 2022 |
| Balance 5 Ltd | Education | 2022 |
| Balance on Edges Ltd | Extraterritorial | 2024 |
| Balas Properties Ltd | Real estate | 2026 |
| Balham Gardeners Ltd | Administrative & support | 2026 |
| Balham Joinery Ltd | Manufacturing | 2015 |
| Balm of Gilead Healing Ministries | Other services | 2009 |
| BAM Contractors Ltd | Construction | 2025 |
| Bamboo Digital Ltd | Information & communication | 2014 |
| Bamboo Grove Health Ltd | Health & social care | 2014 |
| Bamboo Sets Limited | Manufacturing | 2025 |
| Bamboozy Limited | Wholesale & retail | 2025 |
| Banana Productions Limited | Hospitality | 2007 |
| Bao-Ling Ltd | Health & social care | 2023 |
| Barath UK Ltd | Wholesale & retail | 2011 |
| Barber Affiliate Limited | Wholesale & retail | 2019 |
| Bargains.On.Us Ltd | Information & communication | 2024 |
| Barista Putney Limited | Wholesale & retail | 2016 |
| Baron Grove (Mitcham) Residents Company Limited | Real estate | 2000 |
| Baruwa and Co Limited | Real estate | 2026 |
| Bash London Trading Ltd | Transport & logistics | 2021 |
| Bashir Property Investments Ltd | Real estate | 2021 |
| Basil IKE Limited | Health & social care | 2018 |
| Bathroom Warehouse UK Limited | Water & waste | 2007 |
| Battersea Aesthetics Ltd | Health & social care | 2024 |
| Bazaari Limited | Other services | 2012 |
| Bazarizz Ltd | Other services | 2025 |
| BC & AC Clapham Ltd | Other services | 2025 |
| BCC Autos Ltd | Wholesale & retail | 2023 |
| BCD Food Limited | Hospitality | 2019 |
| BE Dazed Ltd. | Extraterritorial | 2015 |
| BE Skilledin Services Ltd | Administrative & support | 2020 |
| Beastie Pictures Ltd | Information & communication | 2023 |
| Beat the Retail Ltd | Wholesale & retail | 2025 |
| Beats and Cleats Ltd. | Professional & scientific | 2018 |
| Beaunexa Limited | Wholesale & retail | 2026 |
| Beauty Bells Ltd | Other services | 2019 |
| Beauty Shop Londn Ltd | Wholesale & retail | 2023 |
| BEAUTY4U Ltd | Wholesale & retail | 2020 |
| Beaverbrook ( London ) Ltd | Real estate | 2024 |
| Beddington Consultants Limited | Professional & scientific | 2023 |
| BEE Colours Ltd | Construction | 2024 |
| Beecholme Adult Care Ltd | Health & social care | 2011 |
| Beek Digital Studios Limited | Information & communication | 2023 |
| Beetatec Ltd | Information & communication | 2011 |
| Behzad Stores Limited | Wholesale & retail | 2025 |
| Being Human Ventures Ltd | Administrative & support | 2024 |
| Bello Electrics Ltd | Construction | 2023 |
| Beluci Electrical Service Limited | Construction | 2023 |
| BEN Malone Music Ltd | Information & communication | 2024 |
| Benele Ltd | Manufacturing | 2021 |
| Benk Homes Limited | Real estate | 2025 |
| Beno Removals Ltd | Transport & logistics | 2024 |
| Berin Properties Company Ltd | Real estate | 2024 |
| Besh Teck Ltd | Information & communication | 2026 |
| Bespoke Metalcraft Ltd | Manufacturing | 2020 |
| Bespoke Mortgage Advice Ltd | Financial services | 2012 |
| Bespoke Pipe Welding Solutions Ltd | Construction | 2015 |
| Best at Home Domiciliary Care Services Ltd | Health & social care | 2016 |