| Harriet Crane Limited | Professional & scientific | 2023 |
| Havelock Place Management (Whitby) Limited | Households | 1997 |
| Hayscarth V.R.C. Limited | Administrative & support | 2001 |
| Heat Floors Limited | Construction | 2018 |
| HEC Engineering Ltd | Construction | 2024 |
| Helping Hands (Redcar & Cleveland) Limited | Health & social care | 2026 |
| Heritage Hearthstone Fires and Stoves Limited | Wholesale & retail | 2020 |
| High Farm Glamping Ltd | Hospitality | 2024 |
| Highcliff Electrical Ltd | Construction | 2025 |
| Highcliff Homes Ltd | Real estate | 2023 |
| Highcliffe Building Solutions Ltd | Construction | 2024 |
| Highcliffe Developments Limited | Real estate | 2016 |
| Highcliffe View (Guisborough) Management Company Limited | Households | 2015 |
| Hirst Groundworks Limited | Other services | 2014 |
| HLF Technical Services Limited | Mining & quarrying | 2016 |
| Hodgkiss Optical Services Limited | Health & social care | 2018 |
| Hollins Stables Limited | Agriculture & fishing | 2022 |
| Homes 247 Ltd | Information & communication | 2019 |
| Hopewell Restaurant Limited | Hospitality | 2019 |
| House Ancestry Limited | Administrative & support | 2026 |
| Hudson Group Developments Ltd | Construction | 2025 |
| Hunters Hill Farm Management Company Limited | Real estate | 2015 |
| Huss Ltd | Administrative & support | 2017 |
| Hutton Chemicals Limited | Manufacturing | 1991 |
| Hutton Field Services Ltd | Professional & scientific | 2018 |
| Hutton Gate Property Ltd | Real estate | 2014 |
| Hutton Petrochemicals Ltd | Manufacturing | 2015 |
| Hyd-Tech Ltd | Administrative & support | 2023 |
| I P Crane Limited | Agriculture & fishing | 2023 |
| IDK Management Limited | Professional & scientific | 2014 |
| Industry Solutions Consulting Ltd | Information & communication | 2021 |
| Infinity Digital Services Limited | Information & communication | 2019 |
| Infinity Environmental Solutions Limited | Water & waste | 2014 |
| Inkedin Studio Ltd | Other services | 2025 |
| Inspirational Interiors (N.E.) Ltd | Wholesale & retail | 2018 |
| Inspire in the Community CIC | Manufacturing | 2023 |
| Instrument & Control Engineering Solutions Limited | Professional & scientific | 2012 |
| Invierno Limited | Administrative & support | 2016 |
| Iron Hills Gym Ltd | Arts & recreation | 2025 |
| J & J Property Restorations Limited | Construction | 2026 |
| J B Hutton Construction Limited | Construction | 2016 |
| J Harleys Ltd | Manufacturing | 2012 |
| J&S Plant Hire Ltd | Administrative & support | 2022 |
| J.D.M Ventures Ltd | Wholesale & retail | 2025 |
| Jacob Winspear Ltd | Construction | 2023 |
| James Hatton Limited | Construction | 2013 |
| James Riley Group Ltd | Real estate | 2026 |
| Jamie Mcintyre Mcdonald Limited | Professional & scientific | 2014 |
| JC Cosmetics Ltd | Health & social care | 2020 |
| JCL Heating Ltd | Construction | 2021 |
| JD Engineering North East Limited | Professional & scientific | 2026 |
| JJL Healthcare & Aesthetics Limited | Professional & scientific | 2025 |
| JJW Recovery Ltd | Wholesale & retail | 2024 |
| JL Educational Consultancy Ltd | Education | 2022 |
| JLB Engineering Ltd | Manufacturing | 2017 |
| JLR Services Ltd | Construction | 2026 |
| JMH Quantity Surveying Services Ltd | Professional & scientific | 2025 |
| JMQ Instruments Limited | Other services | 2016 |
| JMQ Lettings Limited | Real estate | 2022 |
| JOE Robinson Instrumentation Ltd | Professional & scientific | 2020 |
| Johnson's Yard Management Company (Guisborough) Limited | Households | 2004 |
| Jonah Finishing Solutions Limited | Construction | 2021 |
| Jones and Father Limited | Manufacturing | 1989 |
| Jones Electrical Technologies Limited | Manufacturing | 2015 |
| JP Generator Services Ltd | Construction | 2022 |
| Jpas Property Limited | Real estate | 2022 |
| JPD PUB Company Ltd | Professional & scientific | 2025 |
| JR Construction (North East) Ltd | Construction | 2022 |
| JS Offshore Jointing Services Ltd | Construction | 2023 |
| JSH Welding Ltd | Manufacturing | 2026 |
| JT Groundworks and Utilities Limited | Construction | 2020 |
| JT Groundworks Holdings Limited | Financial services | 2021 |
| JT Northern Ltd | Wholesale & retail | 2020 |
| Jtaylerson Limited | Professional & scientific | 2016 |
| Julie Phillips Ltd | Education | 2013 |
| Juray Properties Ltd | Real estate | 2023 |
| Just Dents Teesside Limited | Other services | 2019 |
| Just Fires Limited | Construction | 2006 |
| JWG Rope Access Solutions Ltd | Construction | 2019 |
| K Durant Accountants Ltd | Professional & scientific | 2018 |
| Kamet Limited | Other services | 2014 |
| Kamtech Engineering Ltd | Construction | 2010 |
| KAS Professional Services Limited | Information & communication | 2009 |
| KB Building & Renovation Limited | Construction | 2024 |
| Kdkh Leisure Ltd | Hospitality | 2021 |
| KE Property Holdings Ltd | Administrative & support | 2019 |
| Keamore Limited | Information & communication | 2008 |
| KEN Smith Sales Limited | Other services | 2012 |
| Kendra Dodd Limited | Hospitality | 2024 |
| Kerv Lite Limited | Information & communication | 2021 |
| Kevin Edward Consultancy Limited | Administrative & support | 2015 |
| Kevin Patton Tree Surgeon Limited | Professional & scientific | 2006 |
| Key to Education Ltd | Education | 2025 |
| Khoingo Nails Ltd | Other services | 2026 |
| Kiddiwinks 16 Ltd | Education | 2016 |
| KLS Leisure Limited | Hospitality | 1997 |
| KM Construction Management Limited | Construction | 2024 |
| Koselig Ltd | Manufacturing | 2021 |
| Kwik Cash Limited | Administrative & support | 1998 |
| Kwik Kash Limited | Administrative & support | 1998 |