| Harpenden Secondary Education Trust | Harpenden | 2014 |
| Harpenden Tutors Limited | Leighton Buzzard | 2010 |
| Harper Adams University | Newport | 2012 |
| Harper and Hallie Ltd | Northwich | 2025 |
| Harper Craven Associates Limited | Manchester | 1989 |
| Harper ED Ltd | Totnes | 2026 |
| Harper Horizons Ltd | Wells | 2024 |
| Harper Learning Ltd | Oldham | 2024 |
| Harper-Quinn Ltd | Faringdon | 2022 |
| Harpers ED UK Ltd | Tonbridge | 2025 |
| Harpers Risk Management/ Training and Safeguarding Ltd | London | 2026 |
| Harpurs Hill Children and Family Centre Limited | Coleraine | 2000 |
| Harrence Limited | Solihull | 2025 |
| Harriet Emily Limited | London | 2020 |
| Harriet Harper Associates Limited | London | 2014 |
| Harriet House Montessori School Limited | Thatcham | 2009 |
| Harriet Maydew Psychology Limited | Coventry | 2024 |
| Harriet Multi Academy T Ltd | London | 2025 |
| Harriet Stokes Education Limited | Stockport | 2021 |
| Harrington Morgan Limited | Bury St. Edmunds | 2002 |
| Harrington Safety Ltd | Uxbridge | 2015 |
| Harringtons Learning Centre C.I.C. | Nelson | 2016 |
| Harris Academies Project Management Limited | Croydon | 2006 |
| Harris Education Limited | Coalville | 2006 |
| Harris Federation | Croydon | 2007 |
| Harris HR & Staff Training Ltd | Sutton Coldfield | 2015 |
| Harris Leadership and Training in Surgery Ltd | Pershore | 2021 |
| Harris Learning Solutions Ltd | Oswestry | 2025 |
| Harris Rheumatology Services Ltd | Edinburgh | 2019 |
| Harris Safety Training Limited | Middlesbrough | 2024 |
| Harris Training & Consulting Ltd | Newhall | 2016 |
| Harrison & York Publishing Ltd | London | 2013 |
| Harrison College Limited | Doncaster | 2019 |
| Harrison Health and Education Ltd | London | 2023 |
| Harrison Holdings Pembrokeshire Ltd | Llanreath | 2019 |
| Harrison Lowe Limited | Guildford | 2011 |
| Harrison Network Limited | Cockermouth | 2017 |
| Harrisonspencer Ltd | Preston | 2014 |
| Harrods Education Limited | Welling | 2018 |
| Harrogate Child Entertainment Limited | Knaresborough | 2019 |
| Harrogate Education Limited | London | 2024 |
| Harrogate Ladies' College Limited | Harrogate | 1924 |
| Harrogate Preparatory School Limited | London | 1999 |
| Harrogate Racquets Club Limited | Harrogate | 2021 |
| Harrogate School of Swimming Limited | Leeds | 2014 |
| Harrogate Tuition Limited | Nelson | 2024 |
| Harrold Cricket Club CIC | Harrold | 2024 |
| Harrow Club | London | 1996 |
| Harrow Driving School Ltd | Harrow | 2024 |
| Harrow Education Centre Ltd | Harrow | 2024 |
| Harrow Educational Investments Limited | Harrow | 2021 |
| Harrow High School | Harrow | 2011 |
| Harrow Independent College Limited | Harrow | 2014 |
| Harrow Learning Centre Ltd | Harrow | 2020 |
| Harrow North and South First Class Learning Ltd | Pinner | 2025 |
| Harrow Primary Hub Ltd | Harrow | 2024 |
| Harrow Teacher Training Limited | Wokingham | 2022 |
| Harrow Tutorial College Limited | Harrow | 2010 |
| Harrow Tutorial Limited | Harrow | 2013 |
| Harrow Young Musicians | Aylesbury | 1997 |
| Harry Birrell Scholarship Trust Limited | Sevenoaks | 1997 |
| Harry Cliff Limited | London | 2025 |
| Harry Duthie Ltd | Bakewell | 2019 |
| Harry Giles Tutoring Limited | London | 2021 |
| Harry Johnson Limited | Stoughton | 2022 |
| Harry's Amazon MAP Ltd | Addlestone | 2023 |
| Harry's Driving School Ltd | Wembley | 2025 |
| Harry's Helpers Limited | South Woodham Ferrers | 2024 |
| Harry's Poetryy Limited | Newbury | 2026 |
| Harry's Tutoring Academy Ltd | Falkirk | 2025 |
| Harrybockarie Ltd | London | 2019 |
| Harry’S HQ Barbering Academy Ltd | Littleborough | 2026 |
| Hart Athletic Performance Ltd | London | 2025 |
| Hart Common PRE School Ltd | Manchester | 2018 |
| Hart Employment Services Limited | Letchworth Garden City | 1994 |
| Hart Golf Limited | Glasgow | 2026 |
| Hart Hkers FC CIC | Fleet | 2024 |
| Hart Investing Ltd | Newton Abbot | 2025 |
| Hart Performance Coaching Limited | Preston | 2024 |
| Hart Street Limited | London | 2023 |
| Hart Worldwide Limited | Cambridge | 2025 |
| Hartcliffe & Withywood Ventures | Bristol | 1985 |
| Hartcliffe Coderz CIC | Bristol | 2024 |
| Harte 2 Harte Ltd | Brighton | 2025 |
| Hartismere Family of Schools | Eye | 2010 |
| Hartlane School of Motoring Ltd | Luton | 2019 |
| Hartle Bryggen Ltd | Buckingham | 2025 |
| Hartlepool Aspire Trust | Hartlepool | 2013 |
| Hartlepool Regeneration Group Limited | Hartlepool | 2018 |
| Hartlepool Sport CIC | Hartlepool | 2020 |
| Hartlepool Training Limited | Hartlepool | 2020 |
| Hartley & Gordon Nurseries Limited | Blairgowrie | 2013 |
| Hartley and Whitmore Limited | Grimsby | 2026 |
| Hartley Arts Group | Hook | 2010 |
| Hartleyites Sports Club UK | Warwick | 2020 |
| Hartleys Academy Limited | Liverpool | 2025 |
| Hartlip Driving School Ltd | Gillingham | 2025 |
| Hartlip HGV Driving School Ltd | Gillingham | 2022 |
| Hartmore Education Limited | Corse | 2000 |
| Hartmore Genesis Limited | Gloucester | 2023 |