| Handyman (Louth and Alford) Limited | Wholesale & retail | 2002 |
| Harrington Estates Driby Limited | Agriculture & fishing | 1997 |
| Harrington Hall Farms Limited | Agriculture & fishing | 1996 |
| Harris Beds (Grantham) Ltd | Wholesale & retail | 2010 |
| Harrison Group Limited | Extraterritorial | 2006 |
| Harrisons Security Holdings Limited | Extraterritorial | 2007 |
| Harving Limited | Real estate | 1990 |
| Hatfield Property Services Ltd | Administrative & support | 1996 |
| Hazlewell Road Limited | Financial services | 2021 |
| Heat-Seal Trade Windows Limited | Manufacturing | 2002 |
| Heatech Services Limited | Professional & scientific | 2009 |
| Henry Bell & Co (Grantham) Limited | Manufacturing | 1981 |
| Henry Ramsbottom Ltd | Extraterritorial | 1987 |
| Hickson Fresh Foods Ltd | Wholesale & retail | 2003 |
| Hill Crest Eggs Limited | Agriculture & fishing | 2007 |
| Hill Holt in the Community Limited | Agriculture & fishing | 2007 |
| Hill Holt Wood | Education | 2002 |
| Hillcrest Restorations Limited | Construction | 2007 |
| Hindmarch & Co. (Stamford) Limited | Wholesale & retail | 1972 |
| Hodgson Properties Limited | Real estate | 2002 |
| Holbeck Manor Properties Limited | Households | 2000 |
| Holywell Footwear Limited | Transport & logistics | 1984 |
| Home Farm (Witham on the Hill) Management Company Limited | Households | 2005 |
| Homeservice Heating and Plumbing Limited | Wholesale & retail | 1984 |
| Hood Parkes & Co Ltd | Professional & scientific | 2012 |
| Hopkins Group Limited | Wholesale & retail | 1985 |
| Horncastle and District Indoor Bowls Club Limited | Arts & recreation | 1989 |
| Horncastle Community Members Squash Club Limited | Arts & recreation | 2007 |
| Horncastle Tiles Limited | Wholesale & retail | 2002 |
| Hornsby Storage Limited | Administrative & support | 2002 |
| Horsley & Co. (Gainsborough) Limited | Wholesale & retail | 2004 |
| Hortic Express Limited | Wholesale & retail | 1999 |
| Hot Roast and Farmhouse Bakery Limited | Wholesale & retail | 2003 |
| HTS Developments Limited | Wholesale & retail | 2007 |
| Humber Investment Limited | Construction | 1959 |
| Humber Limited | Manufacturing | 2007 |
| Humber Motor Company Limited | Manufacturing | 2007 |
| Hutsons Limited | Manufacturing | 1946 |
| HV Power Management Limited | Professional & scientific | 2014 |
| IAN Draper Consulting Limited | Professional & scientific | 2022 |
| IAN Tasker Joinery Ltd | Construction | 2002 |
| IAN Wood Ltd | Construction | 2003 |
| Ideal Office Interiors Limited | Professional & scientific | 2000 |
| Ideal Storage and Partitioning Limited | Construction | 1992 |
| Idgrang Limited | Real estate | 1987 |
| IMP Travel Limited | Administrative & support | 1982 |
| Impact (Boston) Limited | Manufacturing | 1964 |
| Imperial Teas of Lincoln Ltd | Administrative & support | 2003 |
| Inflected Limited | Information & communication | 2011 |
| Inscape Limited | Construction | 2001 |
| Inspiring Leadership Foundation Ltd | Professional & scientific | 2022 |
| IQ Skegness Ltd | Wholesale & retail | 2019 |
| Izhar Barber Limited | Other services | 2025 |
| J & a (International) Limited | Manufacturing | 1981 |
| J & a Europe Limited | Extraterritorial | 1978 |
| J & R LEE (Park Homes) Limited | Hospitality | 2003 |
| J + S Adhesives Limited | Manufacturing | 1996 |
| J D E Services Limited | Manufacturing | 2003 |
| J Hodgson & Sons Ltd. | Construction | 1999 |
| J O Sims Limited | Wholesale & retail | 1986 |
| J S Capital Limited | Administrative & support | 1984 |
| J Willson Limited | Other services | 2006 |
| J. & R. Emerson Limited | Agriculture & fishing | 1976 |
| J. H. Baxter & Sons Limited | Agriculture & fishing | 2005 |
| J.Carr & SON Limited | Wholesale & retail | 1964 |
| J.E.Draper Limited | Wholesale & retail | 1955 |
| J.R.Bishop (Moulton) Limited | Real estate | 1950 |
| James Edgar Historic Buildings Consultants Ltd | Professional & scientific | 2014 |
| James Harvey Jewellers (Bourne) Limited | Wholesale & retail | 2000 |
| JAY Hawkins Plumbing & Heating Engineer Limited | Construction | 2005 |
| JD Johnson Limited | Agriculture & fishing | 2004 |
| JET TEC International Limited | Professional & scientific | 1996 |
| JIM Wright Engineering Limited | Construction | 2002 |
| JK Garage Equipment Ltd | Wholesale & retail | 2016 |
| JKL Advisory Services Limited | Professional & scientific | 2005 |
| John Darke Limited | Wholesale & retail | 1956 |
| John LEE (Trading) Limited | Professional & scientific | 1981 |
| John Nelson & Sons Limited | Wholesale & retail | 2003 |
| JPD Engineering (Southwell) Limited | Agriculture & fishing | 2007 |
| K B Installations (Upvc) Limited | Construction | 2007 |
| K Trading Limited | Administrative & support | 2003 |
| Kay's Construction and Security Limited | Construction | 2018 |
| KB Sports Car Hire Limited | Arts & recreation | 2005 |
| KDC Project Management Limited | Professional & scientific | 2007 |
| Keltoon Limited | Wholesale & retail | 2026 |
| KEN Briggs Ltd | Wholesale & retail | 2003 |
| Kenateam Limited | | 1982 |
| Kenbal Hodgson Limited | Extraterritorial | 1998 |
| Kenbal Properties Limited | Extraterritorial | 1963 |
| Kess Agaya Global Ltd | Wholesale & retail | 2025 |
| Kiowa Group Holdings Limited | Financial services | 2020 |
| Kitsch Kiosk Limited | Professional & scientific | 2024 |
| Kobek Limited | Information & communication | 1992 |
| Kurdish Barber Fade Ltd | Other services | 2020 |
| L Brackenbury and SON Limited | Wholesale & retail | 2003 |
| L J Services Limited | Construction | 2002 |
| Lachina Properties Limited | Construction | 1960 |
| Lakeside Hotel (Skegness) Limited | Hospitality | 2003 |
| Land Network (North East Lincolnshire) Limited | Water & waste | 2005 |
| Landmark Trading (Stamford) Limited | Wholesale & retail | 2006 |