| 1ST Financial Limited | Financial services | 2000 |
| 1ST Flooring Limited | Construction | 2017 |
| 1ST Folding Sliding Holdings Limited | Financial services | 2023 |
| 1ST for Accounting Ltd | Professional & scientific | 2022 |
| 1ST for Property Ltd | Professional & scientific | 2004 |
| 1ST for Resin Limited | Construction | 2023 |
| 1ST for Storage Limited | Other services | 1998 |
| 1ST Formations Limited | Administrative & support | 2014 |
| 1ST Framework | Health & social care | 1994 |
| 1ST Front Door Security Ltd | Administrative & support | 2023 |
| 1ST FSD Group Ltd | Construction | 2022 |
| 1ST Gents Earls CUT Ltd | Other services | 2025 |
| 1ST Gold Limited | Other services | 2024 |
| 1ST Golden Persian Massage Therapy Ltd | Other services | 2025 |
| 1ST Growth Consulting Ltd | Professional & scientific | 2013 |
| 1ST Grup Ltd | Construction | 2026 |
| 1ST Guard Limited | Other services | 2024 |
| 1ST Heritage Consultancy Ltd | Professional & scientific | 2024 |
| 1ST Housing Solution C.I.C. | Hospitality | 2019 |
| 1ST Icon Ltd | Manufacturing | 2018 |
| 1ST International Limited | Wholesale & retail | 2021 |
| 1ST Internet Limited | Other services | 2024 |
| 1ST Internet Systems Limited | Other services | 2026 |
| 1ST IT People Ltd | Extraterritorial | 2006 |
| 1ST K9 Security Limited | Administrative & support | 2022 |
| 1ST Kensal Green Boys Brigade and Girls Association | Health & social care | 2025 |
| 1ST Knight Limited | Other services | 2026 |
| 1ST Legacy Estates Ltd | Financial services | 2019 |
| 1ST Lettings Ltd | Real estate | 2003 |
| 1ST Line Consulting Ltd | Professional & scientific | 2010 |
| 1ST Line Properties Ltd | Real estate | 2026 |
| 1ST Live Ltd | Information & communication | 2024 |
| 1ST Local Window Repair Ltd | Construction | 2026 |
| 1ST Locums Limited | Health & social care | 2008 |
| 1ST Loft Ltd | Construction | 2020 |
| 1ST Logic Limited | Information & communication | 2017 |
| 1ST Logistic Solutions Ltd | Administrative & support | 2025 |
| 1ST London Ltd | Construction | 2019 |
| 1ST Luxury Limited | Other services | 2025 |
| 1ST Maintain Ltd | Construction | 2025 |
| 1ST Media Hosting Ltd | Information & communication | 2011 |
| 1ST Medic Limited | Other services | 2024 |
| 1ST Metropolitan Locksmiths Limited | Administrative & support | 1991 |
| 1ST Mile Ltd | Other services | 2006 |
| 1ST Mobile Limited | Other services | 2026 |
| 1ST Mobile Tyre Fitting Ltd | Wholesale & retail | 2025 |
| 1ST Move Services Limited | Real estate | 2022 |
| 1ST Nails Spa & Beauty Ltd | Other services | 2019 |
| 1ST Nation Limited | Other services | 2024 |
| 1ST National Associates Limited | Other services | 2022 |
| 1ST National Services Limited | Other services | 2026 |
| 1ST National Solutions Limited | Other services | 2025 |
| 1ST National Trading Limited | Other services | 2022 |
| 1ST Natural Limited | Other services | 2024 |
| 1ST Nature Limited | Real estate | 2022 |
| 1ST Nephi Ltd | Transport & logistics | 2025 |
| 1ST NET International Limited | Other services | 2025 |
| 1ST Network Limited | Other services | 2021 |
| 1ST North Limited | Other services | 2024 |
| 1ST Online Solutions Limited | Professional & scientific | 2009 |
| 1ST Option Coin Ltd | Professional & scientific | 2020 |
| 1ST Option Representation Limited | Professional & scientific | 2000 |
| 1ST Pension Services Limited | Professional & scientific | 2025 |
| 1ST Pixel Ltd | Administrative & support | 2025 |
| 1ST Place Children and Parents' Centre Ltd. | Education | 2005 |
| 1ST Play Ltd | Arts & recreation | 2025 |
| 1ST Plumbers Ltd | Construction | 2023 |
| 1ST Point Fire Security Ltd | Administrative & support | 2024 |
| 1ST Point Properties Ltd | Hospitality | 2018 |
| 1ST Point Restaurant Ltd | Hospitality | 2025 |
| 1ST Point Training Education & Consultancy Ltd | Education | 2020 |
| 1ST Point Training Limited | Education | 2008 |
| 1ST Policy Lond Limited | Financial services | 2009 |
| 1ST Power Limited | Other services | 2024 |
| 1ST Press Limited | Other services | 2024 |
| 1ST Prestige Care Ltd | Administrative & support | 2014 |
| 1ST Properties Limited | Extraterritorial | 2004 |
| 1ST Property Ltd | Households | 2021 |
| 1ST Property Solutions Limited | Real estate | 2018 |
| 1ST Quality Fabrication & Engineering Ltd | Manufacturing | 2012 |
| 1ST Quality Recovery Limited | Transport & logistics | 2019 |
| 1ST Rapid Property Services Ltd | Administrative & support | 2013 |
| 1ST Rate Investment (UK) Limited | Financial services | 2004 |
| 1ST Rate Properties Limited | Real estate | 2022 |
| 1ST Red Limited | Other services | 2024 |
| 1ST REP Holdings Ltd | Other services | 2025 |
| 1ST Response Building Maintenance Ltd | Construction | 2022 |
| 1ST Response Maintenance Ltd | Construction | 2025 |
| 1ST Response Site Services Limited | Manufacturing | 2011 |
| 1ST Rock Ltd | Real estate | 2024 |
| 1ST Route Limited | Professional & scientific | 2012 |
| 1ST Scope Ltd | Construction | 2024 |
| 1ST Sentry Group Ltd | Administrative & support | 2025 |
| 1ST Shield Security Service Limited | Administrative & support | 2022 |
| 1ST Silver Limited | Other services | 2024 |
| 1ST Soft Limited | Information & communication | 2019 |
| 1ST Solution Consultancy Ltd | Professional & scientific | 2024 |
| 1ST Solution Contractors Ltd | Construction | 2011 |
| 1ST Solution GAS and Plumbing Ltd | Construction | 2026 |
| 1ST Solution Services Ltd | Construction | 2015 |