| Firs and Bromford Community Development Trust C.I.C. | Birmingham | 2022 |
| First & Foremost Entertainment Limited | Braintree | 2011 |
| First & Foremost Events Limited | Braintree | 2014 |
| First & Foremost Limited | Braintree | 2019 |
| First & Last Creative Studios Ltd | Nottingham | 2025 |
| First & Last Music Limited | London | 2016 |
| First & Last Words Ltd | Woking | 2025 |
| First & Only Events Limited | Manchester | 2014 |
| First 1 Club Ltd | Richmond | 2010 |
| First 4 Futsal CIC | Hull | 2021 |
| First 4 Sports & Leisure Limited | Fleet | 2003 |
| First ACT Arts Limited | Runcorn | 2021 |
| First ACT Theatre | Newcastle Upon Tyne | 1992 |
| First Advantage Tennis Ltd | Colwyn Bay | 2014 |
| First AID Art Limited | London | 2005 |
| First and Only Airsoft Limited | Manchester | 2010 |
| First Black Frame Limited | Worcester Park | 2012 |
| First Call (Housing Consultants) Limited | London | 1994 |
| First Call Crew Ltd | Towcester | 2017 |
| First Call Rigging Limited | Swindon | 2019 |
| First Century Events Ltd | Chester | 2019 |
| First Class Competitions UK Limited | Tiverton | 2024 |
| First Class Consultants Ltd | Newham | 2026 |
| First Class Cricket Coaching Limited | Wakefield | 2011 |
| First Class Fitness Ltd | Dorchester | 2018 |
| First Class Gym Limited | Bridgend | 2004 |
| First Class Marketing Limited | London | 2019 |
| First Class Sailing Limited | Southampton | 2005 |
| First Class Simulations Limited | Banbury | 2004 |
| First Class Sports Coaching & Training Limited | Burnley | 2017 |
| First Class Worldwide Limited | Nottingham | 2012 |
| First CUT Music Limited | Northampton | 2011 |
| First Dance Limited | Farnham | 2003 |
| First Dance ZR Ltd | Cradley Heath | 2025 |
| First Flights Media Limited | Stroud | 2019 |
| First Floor Entertainment Limited | Salford | 2026 |
| First Floor Productions Limited | London | 2025 |
| First Football Coaching Academy Ltd | Bury | 2020 |
| First for Events Ltd | Manchester | 2018 |
| First for Players Limited | Penrith | 2016 |
| First Frontier Ltd | Birmingham | 2020 |
| First Furthest Fastest Limited | Birmingham | 2024 |
| First Goal Events Limited | Hitchin | 2014 |
| First Grade Coaching Limited | Ashby-De-La-Zouch | 2005 |
| First Grade Sports Limited | Ashby-De-La-Zouch | 2011 |
| First Gymnastics Newcastle Ltd | Birmingham | 2024 |
| First Gymnastics South Manchester Limited | Wirral | 2024 |
| First Hand International Limited | London | 2020 |
| First Impact Limited | Southall | 2018 |
| First Impressions Theatre Limited | Lancaster | 2024 |
| First in Events Limited | Northampton | 2020 |
| First in Last OUT Touring Limited | Leigh-On-Sea | 2022 |
| First in Music Ltd | Isleworth | 2009 |
| First International Claims Filing Ltd | London | 2018 |
| First Kicks Events Limited | Billericay | 2022 |
| First Light Adventure Ltd | Chesterfield | 2021 |
| First Light Children's Yoga Ltd | Milton Keynes | 2015 |
| First Light Events Limited | Bristol | 2019 |
| First Light Films Ltd | Norwich | 2018 |
| First Love Records Limited | Stockport | 1992 |
| First Network Ltd. | Northolt | 1992 |
| First Nine Golf Limited | London | 2025 |
| First Pass Custom Tattoo Limited | Burton On Trent | 2025 |
| First Point Fitness Ltd | Abingdon | 2022 |
| First Press Limited | Cambridge | 2003 |
| First Prize Games Limited | Rhyl | 1996 |
| First Rate Football Limited | Bassingbourn | 2024 |
| First RAY1 UK Limited | London | 2026 |
| First Realm Limited | Chesterfield | 2022 |
| First Reflection Limited | Harpenden | 1986 |
| First Rodeo Touring Limited | Ferndown | 2009 |
| First Sight Design Limited | Monmouth | 2002 |
| First Sight Theatre Company Ltd | London | 2013 |
| First Soccer Ltd | High Wycombe | 2013 |
| First Space Fitness Ltd | Northwich | 2023 |
| First Splash Limited | Manchester | 2022 |
| First Sprout Ltd | London | 2025 |
| First Star Sports Limited | London | 2019 |
| First Step 2 Fitness Limited | Co. Durham | 2003 |
| First Step GB Limited | Corsham | 2006 |
| First Step Sports Limited | Hull | 2009 |
| First Steps Run Club Ltd | Haywards Heath | 2025 |
| First Steps Sports Club Ltd | London | 2019 |
| First Stride Events Limited | Guildford | 2017 |
| First Strokes Swim Schools Limited | Stanway Colchester | 2001 |
| First STV Ltd | London | 2024 |
| First Take Limited | Harrow | 1989 |
| First Team Footballer Ltd | Leicester | 2025 |
| First TEE Fitness Limited | Clydebank | 2013 |
| First Third Productions Ltd | Droitwich | 2025 |
| First Time Flyers Ltd | London | 2024 |
| First Touch 360 Ltd | Hull | 2021 |
| First Touch FC Limited | London | 2014 |
| First Touch Football Club CIC | Hull | 2022 |
| First Touch Soccer (E.M.) Limited | Peterborough | 1999 |
| First Touch Sport Ltd | Hornchurch | 2019 |
| First Triathlon Ltd | Waterlooville | 2020 |
| First WE Lift Club Ltd | Preston | 2023 |
| First Years FUN Limited | London | 2025 |
| FIRST4SPORT Ltd | Ampthill | 2012 |