| Byard Enterprises Ltd | Nottingham | 2016 |
| Byatlas Group Ltd | London | 2025 |
| Bycen Limited | Whitefield | 1984 |
| BYD CR Holdco Limited | London | 2019 |
| BYE Holdings Limited | Newbury | 2012 |
| Byer & Co. Holdings Ltd | London | 2026 |
| Byerley Group Limited | Warrington | 2016 |
| Byfield Capital Limited | London | 2015 |
| Byford Commercial Finance Ltd. | Bishops Stortford | 2006 |
| Bygate Holdings Limited | St Albans | 2025 |
| Bygo Limited | London | 2014 |
| Bygones Holdings Limited | Wisbech | 2022 |
| Byhiras (Europe) Limited | London | 2011 |
| Byhiras (Middle East) Limited | London | 2023 |
| Byhiras (UK) Limited | London | 2023 |
| Byhiras Group Limited | London | 2011 |
| Byimpact Mortgages Ltd | Harrow | 2026 |
| BYK Investments NO.1 Limited | Swanley | 2013 |
| BYK Investments NO.2 Limited | Swanley | 2013 |
| BYK Investments NO.3 Limited | Swanley | 2013 |
| Byker Holdings Limited | Haltwhistle | 2023 |
| BYL Connect Limited | Hockley | 2022 |
| Byland Holdings Limited | York | 2023 |
| Bylepp Gelt Limited | London | 2025 |
| Bylw Holdings Ltd | London | 2026 |
| BYM Astral Holdings 1 Limited | London | 2021 |
| Byniri Ltd | Llangollen | 2022 |
| BYR Holdings Ltd | Stafford | 2023 |
| Byran Holdings Limited | Borehamwood | 2024 |
| Byrco Limited | Bagshot | 2005 |
| Byren Holdings Limited | Borehamwood | 2014 |
| Byren Investments Limited | Borehamwood | 2014 |
| Byres Group Ltd | Glasgow | 2022 |
| Byrley Ltd | Richmond | 2013 |
| Byrne & Doherty Mortgage Specialists Ltd | Manchester | 2018 |
| Byrne Co Holdings Ltd | Wolverhampton | 2023 |
| Byrne Family Investments Limited | Chichester | 2017 |
| Byrne Financial Services Ltd | St Anne'S On Sea | 2021 |
| Byrne Future Investments Limited | Chelmsford | 2021 |
| Byrne Insurance Services Limited | Newry | 1977 |
| Byrne Leigh Holding Co. Ltd | Twickenham | 2023 |
| Byrne Property (Holdings) Ltd | Chichester | 2017 |
| Byrne Wealth Management Ltd | Rochdale | 2025 |
| Byrne Williams Limited | Milton Keynes | 1998 |
| Byrnecut UK Limited | Guildford | 2018 |
| Byrom Holdings Limited | Manchester | 2016 |
| Byrom Holdings South West Limited | Star | 2020 |
| Byron Acquisitions Ltd | Sheffield | 2022 |
| Byron Ford Ltd | Sandown | 2017 |
| Byron Hayter Holdings Ltd | Milton Keynes | 2022 |
| Byron Longstaff Independent Financial Consultancy Limited | Tyne & Wear | 2003 |
| Byron MAY Holdings Limited | Bedford | 2021 |
| Byron Premier Holdings Limited | Glasgow | 2023 |
| Byrsa Capital Limited | London | 2025 |
| BYS Holdings Limited | London | 2025 |
| Bysr-Group Ltd | Blackpool | 2025 |
| Byssco a Limited | Bagshot | 2012 |
| Byssco Limited | Bagshot | 1988 |
| Bystone Investments Limited | Manchester | 2022 |
| Bytec Group Limited | Pullborough | 2007 |
| Bytecode Labs Ltd | Lancing | 2021 |
| Bytes Technology Group PLC | Leatherhead | 2020 |
| Bytetree Asset Management Limited | East Bergholt | 2020 |
| Bytheway & Co Accountants (Holdings) Limited | Dudley | 2015 |
| Byts Group Limited | Manchester | 2023 |
| BYW Developments Limited | Leicester | 2014 |
| Bywater Finance Ltd | Grantham | 2026 |
| Bywater Group Holdings Limited | Walsall | 2024 |
| Bywater Holdings Ltd | Bristol | 2021 |
| Bywater Investments Limited | Hungerford | 2022 |
| Bywater Lignum Limited | London | 2023 |
| Bywater Management Limited | Hungerford | 2022 |
| Bywater Paradise Limited | London | 2026 |
| Bywater SFC Advisor Ltd | London | 2025 |
| Bywater SFC Fulcrum GP Ltd | London | 2025 |
| Bywater SFC Holdings Ltd | London | 2023 |
| Bywater SFC Investments Ltd | London | 2023 |
| Bywater SFC Management Ltd | London | 2023 |
| Byways Investments Limited | Petersfield | 2016 |
| Bywell Hall Limited | Brighton | 2014 |
| Bywell Ltd | London | 2017 |
| Bywood Trading Ltd | Hornchurch | 2017 |
| Bywyd Bliss Ltd | Bristol | 2020 |
| Byzantine Capital Limited | Daventry | 2018 |
| BZ Actuarial Ltd | Purley | 2024 |
| BZ Astra Holdings Limited | Derby | 2018 |
| BZ Hold Co Limited | Blackburn | 2025 |
| BZ Holdings Limited | Altrincham | 2025 |
| BZ Private Credit Limited | London | 2019 |
| Bzbom Holding UK Ltd | London | 2025 |
| BZC Holdings Ltd | London | 2024 |
| BZD Ltd | Airdrie | 2025 |
| Bzen JET & ML Trading Ltd | London | 2020 |
| BZH Financial Ltd | Peterborough | 2024 |
| BZK UK Holdings Ltd | Wandsworth | 2022 |
| BZM Limited | Staines-Upon-Thames | 2023 |
| BZS Mortgages Ltd | Nottingham | 2023 |
| BZT Properties Ltd | Harrow | 2025 |
| BZX Investments Limited | London | 2006 |
| BZY Holdings Limited | Edgware | 2022 |