| Host & Stay Group Limited | Financial services | 2020 |
| Host & Stay Limited | Administrative & support | 2019 |
| Host & Stay Management Limited | Real estate | 2017 |
| Host & Stay Technologies Limited | Financial services | 2023 |
| Host SO Simple Ltd | Real estate | 2016 |
| Hostberry Limited | Real estate | 2018 |
| Housam Medical Limited | Administrative & support | 2026 |
| House of Aristaeus Ltd | Manufacturing | 2023 |
| Hunley Hall LLP | | 2008 |
| IAS Property Investment Ltd | Real estate | 2023 |
| IFF Electrical Ltd | Construction | 2025 |
| Iliaco Ltd | Professional & scientific | 2019 |
| IN a Pickle Farm Sanctuary CIC | Agriculture & fishing | 2023 |
| Incal Ltd | Construction | 2020 |
| Ingleby's Estate Agents Ltd | Real estate | 2016 |
| Innova Supplements Ltd | Health & social care | 2025 |
| Inspect IT Limited | Professional & scientific | 2016 |
| Into the Calm Limited | Administrative & support | 2025 |
| Invista Trading Ltd | Wholesale & retail | 2023 |
| Iqelevate Ltd | Education | 2025 |
| Iron Coast Ltd | Professional & scientific | 2025 |
| Itla Electrical Limited | Construction | 2021 |
| IU & MD Properties Ltd | Households | 2023 |
| Ivor Valentine Limited | Other services | 2001 |
| Izziebiz Limited | Real estate | 2013 |
| J Greaves Plumbing and Heating Ltd | Construction | 2024 |
| J&B Civils (North East) Ltd | Construction | 2024 |
| J&N Mechanical Limited | Professional & scientific | 2025 |
| J&N Property Management Limited | Real estate | 2020 |
| Jadoo Indian Cuisine Ltd | Hospitality | 2024 |
| JCM Rigging Limited | Construction | 2014 |
| JDR Hospitality Ltd | Hospitality | 2025 |
| Jeeca Property Ltd | Real estate | 2023 |
| Jemsideas Limited | Wholesale & retail | 2015 |
| Jessica Louise Beauty Ltd | Other services | 2022 |
| JG Wind Ltd | Manufacturing | 2021 |
| Jguy Consultancy Limited | Information & communication | 2024 |
| JJB Property Ltd | Real estate | 2025 |
| Jncoaching Limited | Administrative & support | 2026 |
| Joanne Wood Clinical Coding Consultancy Ltd | Information & communication | 2013 |
| John Muir (Saltburn) Holdings Limited | Financial services | 2022 |
| Johnson Plant Services Limited | Construction | 2015 |
| Jolly Sailors Moors Ltd | Hospitality | 2019 |
| JON Nesbitt Limited | Professional & scientific | 2002 |
| Jones Wind & Property Group Ltd | Construction | 2026 |
| JRT Trading Ltd | Wholesale & retail | 2018 |
| JT Damp Proof and Property Maintenance Ltd | Construction | 2025 |
| JT Properties North East Ltd | Real estate | 2026 |
| K Beauty Ltd | Other services | 2014 |
| KAH Agri Services Ltd | Manufacturing | 2026 |
| Kamala Holdings Ltd | Construction | 2023 |
| Kaskane Ltd | Hospitality | 2011 |
| Kasp Inventories Ltd | Real estate | 2023 |
| Keendog Limited | Professional & scientific | 2015 |
| Keystone Civilworks Ltd | Construction | 2023 |
| Kilton Thorpe Specialist Academy | Education | 2012 |
| Kolpe Consulting Ltd | Wholesale & retail | 2019 |
| Koze Saltburn Limited | Hospitality | 2024 |
| Krazy Bars Ltd | Hospitality | 2023 |
| Kryten Engineering Ltd | Professional & scientific | 2024 |
| Ktwo Distribution Limited | Wholesale & retail | 2013 |
| Kyber Tech Ltd | Wholesale & retail | 2025 |
| L&L Access Ltd | Professional & scientific | 2021 |
| L&M Removals Limited | Transport & logistics | 2025 |
| LA Mortgage and Protection Ltd | Financial services | 2022 |
| LA Property & Finance Ltd | Real estate | 2020 |
| LA Rigging (NE) Ltd | Professional & scientific | 2023 |
| Lakeview Hospitality Limited | Hospitality | 2021 |
| Lambel Limited | Hospitality | 2006 |
| Langbaurgh Court Limited | Households | 1986 |
| Laundry Maid Easy Services Ltd | Other services | 2025 |
| Lawson Mech Ltd | Manufacturing | 2025 |
| LD Boland Logistics Ltd | Transport & logistics | 2025 |
| LE Cocq Properties Limited | Hospitality | 2025 |
| Leap Cottages Limited | Real estate | 2017 |
| Leapfrog Lettings Limited | Real estate | 2013 |
| LGA Safety Ltd | Professional & scientific | 2026 |
| Libellule Theatre Ltd | Arts & recreation | 2022 |
| Liberata Bar & Kitchen Limited | Hospitality | 2021 |
| Library of Things Saltburn CIC | Health & social care | 2020 |
| Lindisfarne Medical Ltd | Health & social care | 2019 |
| Lindsey (NE) Limited | Financial services | 2026 |
| Lingdale Engineering Limited | Mining & quarrying | 1999 |
| Liverton Mines Food and Wine Limited | Wholesale & retail | 2025 |
| Living Sober CIC | Health & social care | 2005 |
| LJD Equine & Consultancy Ltd | Professional & scientific | 2026 |
| LM South Yorkshire Limited | Water & waste | 2019 |
| Loftus Barbers Ltd | Other services | 2023 |
| Loftus Large Format Ltd | Manufacturing | 2020 |
| Loftustakeaway Ltd | Hospitality | 2025 |
| Love Loftus CIC | Administrative & support | 2018 |
| LP6 Properties Ltd | Real estate | 2020 |
| LRJ Wind Ltd | Professional & scientific | 2025 |
| M & K Hodgson Ltd | Agriculture & fishing | 2007 |
| M & a Sherwood Limited | Agriculture & fishing | 2010 |
| M & M Property Solutions Ltd | Real estate | 2020 |
| M R M Projects Limited | Professional & scientific | 2007 |
| M Wood Butchers Limited | Wholesale & retail | 2012 |
| M-Tech Vehicle Services Limited | Manufacturing | 2006 |
| Mace Boosbeck Limited | Wholesale & retail | 2011 |