| Hamilton Court (Pinner) Limited | Households | 1989 |
| Hamilton Dock Hotel Limited | Hospitality | 2025 |
| Hamilton Enterprises Limited | Health & social care | 2011 |
| Hamilton Gemmill Limited | Arts & recreation | 2007 |
| Hamilton LEE Properties Ltd | Real estate | 2021 |
| Hamilton LEE Recruitment Consultants Limited | Administrative & support | 2007 |
| Hamilton Young & Co, Ltd | Professional & scientific | 2011 |
| Hamilton-Jones Associates Limited | Administrative & support | 2006 |
| Hamir Enterprises Limited | Real estate | 2018 |
| Hamir Limited | Financial services | 2010 |
| Hamko Ltd | Wholesale & retail | 2026 |
| Hamlet Video International Limited | Manufacturing | 1986 |
| Hamm'R Limited | Information & communication | 2018 |
| Hammer Ua&Uk Ltd | Construction | 2024 |
| Hamoodi Productions Limited | Information & communication | 2018 |
| Hampden Clinics Limited | Health & social care | 2010 |
| Hampden Heating Ltd | Construction | 2025 |
| Hampden Residents Association Limited | Households | 1999 |
| Hampden Residents Limited | Households | 2004 |
| Hamper House Ltd | Wholesale & retail | 2011 |
| Hampshire Place Limited | Real estate | 2026 |
| Hampshire Radiodiagnostics Ltd | Health & social care | 2019 |
| Hampstead London Limited | Hospitality | 2020 |
| Hampton Heating & Plumbing Ltd | Construction | 2010 |
| Hampton Management Limited | Real estate | 2007 |
| Hampton Oak Limited | Professional & scientific | 2021 |
| Hamro Mart Ltd | Wholesale & retail | 2024 |
| Hamson Court Management Company Limited | Households | 1989 |
| Hamza Rehman Associates UK Ltd | Construction | 2024 |
| Hamzah Services Ltd | Other services | 2014 |
| Hana Supplies Limited | Wholesale & retail | 2012 |
| Hanalytics IT Services Limited | Information & communication | 2022 |
| Hanant Limited | Professional & scientific | 2017 |
| Hanatour Europe Limited | Administrative & support | 2003 |
| Hanberry & Co Limited | Extraterritorial | 2010 |
| Hanbridge Limited | Administrative & support | 2000 |
| Hand Car Wash Belmont Ltd | Wholesale & retail | 2016 |
| Hand Car Wash Northwood Limited | Administrative & support | 2017 |
| Hand in Hand Communications Ltd | Professional & scientific | 2026 |
| Hand on Heart Care Services Limited | Health & social care | 2013 |
| Handelnine Global Limited | Wholesale & retail | 2019 |
| Handelson Services Ltd | Real estate | 2024 |
| Handi Technologies Limited | Manufacturing | 2017 |
| Handley Transport Solutions Limited | Transport & logistics | 2017 |
| Hands Discount Limited | Other services | 1959 |
| Hands of Gold Ltd | Construction | 2021 |
| Handstand Global Limited | Wholesale & retail | 2020 |
| Handy 4 London Ltd | Construction | 2026 |
| Handy Cross Hold Co Ltd | Administrative & support | 2020 |
| Handyman SAM Ltd | Construction | 2015 |
| Handyserv Ltd. | Construction | 2015 |
| Hanganu Construction Ltd | Construction | 2020 |
| Hangar Ruding Limited | Households | 1973 |
| Hani Healthcare Limited | Health & social care | 2013 |
| Hanks Automotive Sales and Services Ltd | Wholesale & retail | 2023 |
| Hannah C Consulting Limited | Health & social care | 2026 |
| Hannah Giron Clinical Travels Limited | Health & social care | 2024 |
| Hannah London Beauty Ltd | Other services | 2015 |
| Hannahs Little Cherubs Limited | Education | 2011 |
| Hannan Transport Co Ltd | Transport & logistics | 2025 |
| Hannell's Stores Limited | Wholesale & retail | 1948 |
| Hanover Close (Ashford) Limited | Households | 2013 |
| Hanover Court (Harrow) Limited | Professional & scientific | 2005 |
| Hansa Estates Limited | Real estate | 2006 |
| Hansa Properties Limited | Administrative & support | 2016 |
| Hansai Properties Limited | Real estate | 2015 |
| Hansanj Limited | Health & social care | 2023 |
| Hansavest Solutions Ltd | Administrative & support | 2025 |
| Hansavest UK Limited | Construction | 2025 |
| Hansuk Ltd | Wholesale & retail | 2024 |
| Hantig Construction Ltd | Construction | 2021 |
| Hanumant Trading Limited | Wholesale & retail | 2025 |
| Hanwell Dental Limited | Health & social care | 2020 |
| Hapax Limited | Real estate | 2011 |
| Hapca Construct Ltd | Construction | 2025 |
| Haphzrd Ltd | Information & communication | 2018 |
| Happy Care Plus Ltd | Real estate | 2025 |
| Happy Days After School Club Limited | Health & social care | 2005 |
| Happy Days Pre-School Ltd | Education | 2008 |
| Happy Dog Entertainment Limited | Information & communication | 2004 |
| Happy Ending Pantomimes Limited | Arts & recreation | 2024 |
| Happy Home Contractors Ltd | Construction | 2023 |
| Happy Homes MG Limited | Real estate | 2018 |
| Happy HR People Ltd | Administrative & support | 2023 |
| Happy Media Ltd | Information & communication | 2025 |
| Happy Mummy Limited | Wholesale & retail | 2004 |
| Happy Sailor Tattoos Limited | Administrative & support | 2008 |
| Happy Steps Ltd | Other services | 2013 |
| Happy Tinker Ltd | Wholesale & retail | 2025 |
| Happy Trails Production Limited | Information & communication | 2023 |
| Haps Group Limited | Hospitality | 2026 |
| HAQ Property Enterprise Limited | Real estate | 2021 |
| Haque Investments Ltd | Real estate | 2013 |
| Harai Priya Logistics Ltd | Other services | 2019 |
| Harasp Limited | Administrative & support | 2016 |
| Harbinson UK Limited | Information & communication | 2015 |
| Harbour Property Solutions Ltd | Administrative & support | 2025 |
| Hard Video Systems Limited | Information & communication | 2013 |
| Harding Limited | Hospitality | 1993 |
| Hardwork Cafe Limited | Hospitality | 2002 |