| Bw&L Ltd | Construction | 2025 |
| BWA Water Additives UK Limited | Manufacturing | 2005 |
| Bwaservices Ltd | Education | 2025 |
| BWC Altrincham Ltd | Other services | 2022 |
| BWC Draught Ltd | Hospitality | 2026 |
| BWC Nominee 1 Ltd | Financial services | 2024 |
| BWG Civil Engineering Ltd | Construction | 2018 |
| Bwindi Foundation Ltd | Health & social care | 2022 |
| Bwing Global Ltd | Professional & scientific | 2024 |
| BWR Consulting Limited | Health & social care | 2015 |
| BWS Restaurant Limited | Hospitality | 2023 |
| BXJ Limited | Other services | 2018 |
| BXM Operations Limited | Transport & logistics | 2024 |
| Bxwalker Consulting Ltd | Wholesale & retail | 2022 |
| BY 1 Properties Ltd | Real estate | 2024 |
| BY A.E.C MCR Ltd | Other services | 2023 |
| BY Anything Limited | Information & communication | 2014 |
| BY Beauty Academy Ltd | Other services | 2024 |
| BY Choice Online Limited | Wholesale & retail | 2016 |
| BY Consult Limited | Professional & scientific | 2016 |
| BY Corporate LLP | | 2006 |
| BY Dora Botanicals Ltd | Manufacturing | 2025 |
| BY DR M Ltd | Health & social care | 2025 |
| BY Firdous Ltd | Health & social care | 2018 |
| BY Gamers for Gamers Ltd | Information & communication | 2018 |
| BY Gibz Ltd | Wholesale & retail | 2025 |
| BY Holdings Limited | Real estate | 2026 |
| BY Inspiration Ltd | Information & communication | 2014 |
| BY Letter Limited | Manufacturing | 2021 |
| BY Liberty Limited | Transport & logistics | 2024 |
| BY Louise Nicholson Limited | Professional & scientific | 2025 |
| BY MEL Limited | Professional & scientific | 2025 |
| BY Niamh Boutique & Nail Studio Limited | Wholesale & retail | 2025 |
| BY Olivia JO Limited | Other services | 2025 |
| BY Properties Eccles Ltd | Financial services | 2020 |
| BY the Bar Limited | Hospitality | 2020 |
| BY the Canal Leisure Limited | Hospitality | 2023 |
| BY the River Brewery Ltd | Manufacturing | 2017 |
| By.Tenieka Ltd | Other services | 2025 |
| Byad Consulting Ltd | Professional & scientific | 2008 |
| Byall Technology UK Ltd | Wholesale & retail | 2025 |
| Byas Consulting Limited | Professional & scientific | 2017 |
| Byautoma Ltd | Manufacturing | 2014 |
| Byblos Maintenance Limited | Construction | 2024 |
| Byblos Properties Limited | Construction | 2014 |
| BYC Motors Limited | Wholesale & retail | 2025 |
| Byclecia Ltd | Manufacturing | 2020 |
| Byco Ltd | Wholesale & retail | 2020 |
| BYD Express Ltd | Transport & logistics | 2025 |
| BYD SAS Limited | Information & communication | 2026 |
| Bydand Recruitment Services Limited | Administrative & support | 2015 |
| Bydonizith Ltd | Transport & logistics | 2023 |
| BYE to LET Ltd | Real estate | 2023 |
| Byeco UK Ltd | Construction | 2024 |
| Byers Bros Limited | Construction | 2025 |
| Bygrove Solutions Ltd | Professional & scientific | 2018 |
| Bynd Limited | Information & communication | 2010 |
| Bynde Ltd | Manufacturing | 2026 |
| Bynex Trade Limited | Wholesale & retail | 2024 |
| Bynoto Ltd | Professional & scientific | 2021 |
| Bynural Ltd | Wholesale & retail | 2025 |
| Byoon Ltd | Wholesale & retail | 2025 |
| Byotrol Limited | Professional & scientific | 2005 |
| Byotrol Technology Limited | Wholesale & retail | 2005 |
| Byram Contractors Limited | Extraterritorial | 2021 |
| Byrne & Co. Ltd | Extraterritorial | 2008 |
| Byrne & Doherty Mortgage Specialists Ltd | Financial services | 2018 |
| Byrne Civil Solutions Limited | Construction | 2002 |
| Byrne Services Ltd | Administrative & support | 2022 |
| Byrne's (Chester) Ltd | Wholesale & retail | 2011 |
| Byrnes Interior Systems Limited | Construction | 2025 |
| Byrom Coinvest LP | | 2022 |
| Byrom Holdings Limited | Financial services | 2016 |
| Byrom Street Holdings Limited | Extraterritorial | 2011 |
| Byrom Street Property Limited | Extraterritorial | 2011 |
| Byron 1968 Limited | Extraterritorial | 2014 |
| Byron Green Management Limited | Households | 2007 |
| Byron IT Limited | Information & communication | 2015 |
| Byrsc Ltd | Health & social care | 2026 |
| BYS Developers Ltd | Real estate | 2025 |
| Bysighgel Ltd | Other services | 2020 |
| Bystone Investments Limited | Financial services | 2022 |
| Byte Hub Technology Corporate Ltd | Information & communication | 2025 |
| Bytebox Ltd | Hospitality | 2024 |
| Bytebridge Recruitment Ltd. | Administrative & support | 2024 |
| Bytefen Ltd | Wholesale & retail | 2026 |
| Byteops Ltd | Manufacturing | 2024 |
| Bytes & Tales Ltd | Hospitality | 2026 |
| Bytes Simplified Ltd | Wholesale & retail | 2026 |
| Bytesource Wholesale Ltd | Wholesale & retail | 2025 |
| Bytestrive Solutions Limited | Information & communication | 2025 |
| Bytetribe Ltd | Information & communication | 2025 |
| Bytewell Ltd | Wholesale & retail | 2025 |
| Bytik Ltd | Wholesale & retail | 2025 |
| Byts Group Limited | Financial services | 2023 |
| Bytylerjoi Limited | Other services | 2024 |
| Bywater Wealth Limited | Professional & scientific | 2023 |
| BZ Care Services Limited | Health & social care | 2021 |
| BZ Security Solutions Ltd | Administrative & support | 2026 |
| BZD Properties Ltd | Real estate | 2002 |