| H.Tang Holding Ltd | Financial services | 2025 |
| Hamilton Court (SW5) Management Limited | Households | 1991 |
| Hanhsy Limited | Hospitality | 2022 |
| Hanover Ruislip Limited | Real estate | 2014 |
| Haojing Limited | Hospitality | 2026 |
| Harley Street Osteopaths Limited | Health & social care | 1999 |
| Havila.Express UK Ltd | Wholesale & retail | 2024 |
| HBL 16 London Road RTM Ltd | Households | 2023 |
| Heat Tech Engineers Ltd | Construction | 2025 |
| Hedgeside Limited | Real estate | 2017 |
| Heritage Architecture Limited | Professional & scientific | 1995 |
| Heritage Mews Limited | Real estate | 2014 |
| Heritage Slate Ltd | Extraterritorial | 2021 |
| Hertford CMC Limited | Health & social care | 2021 |
| Hexagon Themetech Limited | Financial services | 2024 |
| Heywood Real Estate (Construction) Limited | Construction | 2015 |
| Heywood Real Estate (ML) Limited | Construction | 2021 |
| Highbrook Capital & Investments Ltd | Construction | 2022 |
| Highbrook Enterprises Ltd | Professional & scientific | 2021 |
| Highbrook Living Ltd | Construction | 2022 |
| Highbrook Properties Ltd | Construction | 2022 |
| Hilbro Capital Ltd | Financial services | 2021 |
| Hilcrest Associates Ltd | Real estate | 2004 |
| Himi Restaurant Limited | Hospitality | 2025 |
| HIT Sport Ltd | Administrative & support | 2020 |
| HK Borehamwood Limited | Hospitality | 2023 |
| Home Recordings Limited | Information & communication | 1995 |
| Hoopoe Management Services Limited | Professional & scientific | 2020 |
| Horizons Resources Ltd | Water & waste | 2019 |
| House of Borscht Ltd | Information & communication | 2021 |
| Housing Answers Limited | Real estate | 2012 |
| HS Consultancy London Limited | Administrative & support | 2013 |
| HT Solutions Ltd | Construction | 2025 |
| HTE Management Limited | Other services | 2019 |
| Hummbirks Ltd | Wholesale & retail | 2016 |
| Humming Bird Motors Limited | Wholesale & retail | 1994 |
| Hung HAO Limited | Hospitality | 2015 |
| Hutchinson & Partners Limited | Professional & scientific | 2017 |
| I Peter Formwork Ltd | Administrative & support | 2016 |
| IBT Solutions Ltd | Manufacturing | 2021 |
| Icebreakers (UK) Ltd | Professional & scientific | 2013 |
| IDA Business Services Limited | Professional & scientific | 2008 |
| Ilford Hand Car Wash Limited | Administrative & support | 2008 |
| Ilhamku Limited | Hospitality | 2026 |
| Immaculate House Limited | Administrative & support | 2006 |
| Impactt Limited | Administrative & support | 1997 |
| Implants Today Limited | Administrative & support | 2006 |
| Independent Locker Solutions Limited | Administrative & support | 2006 |
| International Hospitality Media Limited | Professional & scientific | 2007 |
| International Slate Supplies Limited | Wholesale & retail | 2004 |
| J Hawes Ltd | Real estate | 2021 |
| J Hawes Solutions Ltd | Administrative & support | 2012 |
| J2 Borehamwood Ltd | Hospitality | 2017 |
| JAK Profiles Limited | Wholesale & retail | 2017 |
| James Glancy Design Limited | Professional & scientific | 1990 |
| Jason Investments Limited | Real estate | 1962 |
| JB Lighting Ltd | Energy | 2014 |
| Jeywood Properties Limited | Construction | 2010 |
| Jixiangwu Limited | Hospitality | 2026 |
| JK Locker Solutions Limited | Administrative & support | 2020 |
| Jkskyline Ltd | Construction | 2013 |
| JMP Properties Limited | Administrative & support | 2005 |
| JMW Dentistry Limited | Health & social care | 2022 |
| John Frederick Limited | Administrative & support | 1938 |
| Joobeli Trading Limited | Hospitality | 2022 |
| Joywood Properties Limited | Real estate | 1999 |
| JR Stars Limited | Hospitality | 2022 |
| Jubilee Chinese Limited | Hospitality | 2026 |
| K & Chew Limited | Real estate | 2021 |
| Kenneth Turner Interiors Limited | Wholesale & retail | 2004 |
| Khansullivans Limited | Health & social care | 2023 |
| Kids Gastro Care Limited | Health & social care | 2019 |
| KLN Recycling Ltd | Water & waste | 2020 |
| Kompingo Ltd | Wholesale & retail | 2022 |
| Kophich Solutions Ltd | Information & communication | 2019 |
| Kosher Deli (Hendon) Limited | Manufacturing | 2009 |
| Kosher Deli (Borehamwood) Limited | Wholesale & retail | 2012 |
| Kosher Deli (Manchester) Limited | Wholesale & retail | 2017 |
| Kosher Deli (UK) Limited | Manufacturing | 2007 |
| Kossoff Investments Ltd | Extraterritorial | 2020 |
| Kossoff Trading Ltd | Extraterritorial | 2020 |
| Kossoff's Ltd | Professional & scientific | 2018 |
| Kossoffs (KTR) Ltd | Wholesale & retail | 2020 |
| KS Engineering Services Private Ltd | Construction | 2022 |
| Kubi Holdings Limited | Other services | 2022 |
| Kuromi Tea Limited | Hospitality | 2023 |
| Laluz Ltd | Extraterritorial | 2021 |
| Laluz Slate Ltd | Extraterritorial | 2021 |
| Landview (Bromley) Limited | Construction | 2017 |
| Landview Holdings Limited | Administrative & support | 2012 |
| Landview Properties Limited | Construction | 1997 |
| Landview Property Limited | Construction | 2016 |
| Lawson Luxury Marketing Limited | Professional & scientific | 1986 |
| Lenchner Limited | Financial services | 2014 |
| Lenik Limited | Wholesale & retail | 2021 |
| Lien Consulting Limited | Professional & scientific | 2014 |
| Lime Creative Limited | Professional & scientific | 2002 |
| Link & Go Limited | Administrative & support | 2020 |
| LIZ Collins Ltd | Professional & scientific | 2000 |
| Loanpad Finance Limited | Financial services | 2018 |