| 18 Seconds Ltd | London | 2024 |
| 18 Sports Talent Ltd | London | 2023 |
| 180 Collective Ltd | London | 2023 |
| 180 Degrees Health Clubs Ltd | Poole | 2013 |
| 180 Fitness & Nutrition Limited | Retford | 2019 |
| 180 Fitness Hub Limited | Portland | 2024 |
| 180 Fitness Ltd | Retford | 2022 |
| 180 Recovery Hub Limited | Portland | 2025 |
| 180 Vault Competitions Ltd | Spalding | 2026 |
| 1809512 Limited | Preston | 1984 |
| 1826 Events Limited | Windsor | 2024 |
| 1843 Broadgate Fit Leeds (Leaseco) Limited | Shirebrook | 2025 |
| 1872 Ltd | St. Albans | 2013 |
| 1873 Studios Ltd | London | 2024 |
| 1881 Club CIC | Dalkeith | 2024 |
| 1886 Black Site Ltd | Birkenshaw | 2025 |
| 1899 Inc Limited | London | 2019 |
| 18APR Limited | London | 2018 |
| 19 of Everything Limited | London | 2023 |
| 19 Recordings Limited | London | 1998 |
| 19 Sports Ltd | Harpenden | 2024 |
| 19'40'' Limited | London | 2016 |
| 1900 Entertainment International Limited | Kingston Upon Thames | 2025 |
| 1903 Limited | London | 2021 |
| 1912 Productions Ltd | Southminster | 2024 |
| 1927 Productions Limited | Margate | 2011 |
| 1927CTFC Limited | Birmingham | 2024 |
| 1928 Limited | London | 2018 |
| 192SQFT Goalkeeping Academy UK Ltd | Ashbourne | 2014 |
| 193 Collective Ltd | Burnham-On-Crouch | 2024 |
| 193 Entertainment Ltd | London | 2026 |
| 1936MGMT Ltd | London | 2022 |
| 1939 Vbdb Productions Ltd | Southall | 2023 |
| 1940S Swansea Limited | Ammanford | 2001 |
| 1963 Gallery Space Limited | London | 2016 |
| 1968 Network Limited | Watford | 2017 |
| 1971 Productions Ltd | Wallington | 2026 |
| 1973 Group Ltd | Kington | 2025 |
| 1974 Music Ltd | Hove | 2010 |
| 1981 Events Limited | Dunstable | 2017 |
| 1984 Personal Management Limited | London | 1984 |
| 1985 Music Holdings Ltd | Abingdon | 2025 |
| 1985 Music Ltd | Abingdon | 2019 |
| 1996 Limited | London | 2025 |
| 19IP Limited | Granville Way | 2016 |
| 19TH Century Renaissance CIC | Wetherby | 2026 |
| 19TH Green Ltd | Saltash | 2025 |
| 19TH Hole Golf Group Ltd | Launceston | 2026 |
| 19TH Street Productions Ltd | London | 2015 |
| 1B Strength and Conditioning Ltd | Burscough | 2025 |
| 1BLOCK Events Ltd | Norwich | 2025 |
| 1BODY4LIFE (London) Limited | Ilford | 2014 |
| 1BRELLA Limited | Woking | 2023 |
| 1CM Bleed Ltd | Liverpool | 2012 |
| 1D Media Limited | London | 2010 |
| 1DA Music Limited | Borehamwood | 2025 |
| 1DEGREEEAST Ltd | Canterbury | 2018 |
| 1ELITE Sports Management Ltd | London | 2025 |
| 1IRON Golf Ltd | Milton Keynes | 2017 |
| 1IVE Bull Run Ltd | Cardiff | 2022 |
| 1J Gaming Group Limited | Norwich | 2024 |
| 1K Production Company Limited | London | 2025 |
| 1LIFE Management Solutions Limited | Chorley | 1990 |
| 1LIFEOBIT Limited | London | 2023 |
| 1NFINITY Fitness Limited | Sheffield | 2023 |
| 1NFINITY Limited | Sheffield | 2023 |
| 1NIL Sports Management Ltd | Chelmsford | 2024 |
| 1OAK Events Limited | Sidcup | 2025 |
| 1PUTT Ltd | London | 2017 |
| 1RULE UK Ltd | Ipswich | 2022 |
| 1SCULPT Fitness Ltd | Walton On The Hill | 2018 |
| 1ST Bangor Football Club Limited | Belfast | 2025 |
| 1ST Blood Empire Ltd | Nottingham | 2011 |
| 1ST Call Entertainment Limited | Weston-Super-Mare | 2010 |
| 1ST Call Sams Entertainments Limited | Southampton | 2001 |
| 1ST Choice Animals Ltd | Spalding | 2026 |
| 1ST Choice Speakers UK Ltd | Buckinghamshire | 2005 |
| 1ST Class BET Ltd | London | 2025 |
| 1ST Class Bootcamp Ltd | King'S Lynn | 2022 |
| 1ST Entertainment Ltd. | Chilworth | 2018 |
| 1ST for Hospitality Limited | Bromley | 2019 |
| 1ST Generation Fitness Ltd | South Shields | 2024 |
| 1ST Impressions (Kent) Limited | Dover | 2010 |
| 1ST Play Ltd | London | 2025 |
| 1ST Reaction Academy Ltd | Birmingham | 2016 |
| 1ST Sports Ltd | London | 2015 |
| 1ST TEE Fitness Limited | Bromsgrove | 2025 |
| 1ST to SET Ltd | London | 2023 |
| 1ST Touch Football Coaching Ltd | Eastleigh | 2021 |
| 1ST Touch Football Kickz Limited | Eastleigh | 2025 |
| 1ST Women UK Limited | Wellington | 2009 |
| 1ST4ARTS Limited | Manchester | 2015 |
| 1ST4FITNESS Limited | Bicester | 2015 |
| 1STOPBABYSTORE Ltd | London | 2015 |
| 1UP Esports Limited | London | 2024 |
| 1UP Events Ltd | London | 2025 |
| 1VIGOR (Hipperholme) Ltd | Halifax | 2022 |
| 1VIGOR Limited | Halifax | 2016 |
| 1VOICE1VISION Limited | High Wycombe | 2007 |
| 1VYBE Ltd | London | 2024 |