| Internity Tomorrow Ltd | Hospitality | 2021 |
| Ipenn Haulage Ltd | Transport & logistics | 2025 |
| IQ3K Ltd | Information & communication | 2026 |
| Iron Clown Limited | Information & communication | 2021 |
| Isolex Financial Ltd | Professional & scientific | 2006 |
| Isvara Medical Diagnostics Ltd | Health & social care | 2025 |
| It's Murder Limited | Arts & recreation | 2024 |
| J R Turnbull Ltd | Administrative & support | 2003 |
| J R W Site Services Ltd | Construction | 2016 |
| J&B Roofing Specialists Limited | Construction | 2022 |
| J&N Contracts Limited | Professional & scientific | 2017 |
| J. D. Farnill Limited | Information & communication | 2014 |
| J.Draper Ltd | Construction | 2026 |
| Jackson Engineering (Hull) Limited | Professional & scientific | 2018 |
| Jammin Roots Limited | Hospitality | 2025 |
| JE Hartley Properties Limited | Real estate | 2026 |
| Jeken Limited | Professional & scientific | 2021 |
| Jellies & Wellies Day Nursery Ltd | Education | 2018 |
| JG Physiology Limited | Health & social care | 2022 |
| JGC Data Ltd | Information & communication | 2019 |
| Jhmc Homes Ltd | Construction | 2023 |
| Jiunny Limited | Wholesale & retail | 2023 |
| JJ QP Consultancy Ltd | Professional & scientific | 2018 |
| Jj's Smart Repairs Ltd | Wholesale & retail | 2024 |
| JK5 Limited | Real estate | 2024 |
| JL Nursing Solutions Ltd | Health & social care | 2023 |
| JLS Compliance Group Limited | Financial services | 2025 |
| JMB Site Services Ltd | Construction | 2016 |
| JMH Solutions Limited | Arts & recreation | 2009 |
| JO Musah Ltd | Health & social care | 2023 |
| Jo&El Haulage Ltd | Transport & logistics | 2024 |
| John Bartram Property Limited | Real estate | 2024 |
| JON Payne Ltd | Professional & scientific | 2023 |
| Jopling Group Ltd | Construction | 2024 |
| Jordan Lane Properties Limited | Real estate | 2023 |
| Jordan Pugh Limited | Professional & scientific | 2025 |
| JPK Property Expert Limited | Real estate | 2015 |
| JPL Fabrication Limited | Professional & scientific | 2017 |
| JSA Travel Ltd | Administrative & support | 2026 |
| JST 4 Kidz & Totz Limited | Health & social care | 2010 |
| Jude Limited | Hospitality | 2019 |
| K Living 1 Ltd | Households | 2025 |
| K&S Transport Ltd | Transport & logistics | 2025 |
| K. C. M. Services Limited | Professional & scientific | 1987 |
| K.G.V Cottingham Community Trust | Arts & recreation | 2009 |
| Kaia 11 Limited | Public administration | 2022 |
| Kat's Digital Marketing Ltd | Information & communication | 2024 |
| KB Wealth Planning Ltd | Financial services | 2025 |
| KDF Property Services Ltd | Real estate | 2022 |
| KDM Plumbing Ltd | Construction | 2025 |
| Kelmat Properties Limited | Real estate | 2025 |
| Kendall Accountancy Services Limited | Professional & scientific | 2013 |
| Kesselmann Boiler Cover Ltd | Construction | 2022 |
| Kesselmann Holdings Ltd | Financial services | 2022 |
| Kesselmann Plumbers Ltd | Construction | 2022 |
| Kesselmann Properties Ltd | Real estate | 2026 |
| Key Green Properties Ltd | Real estate | 2017 |
| Khatib Estates Limited | Health & social care | 2022 |
| Kings Entertainment Theatre Limited | Arts & recreation | 2023 |
| Kingston Fire Limited | Professional & scientific | 2021 |
| Kingston Security Services Ltd | Professional & scientific | 2012 |
| Kirmond Holdings Ltd | Real estate | 2025 |
| Kitenji Tours Ltd | Administrative & support | 2025 |
| KK9 Training Ltd | Administrative & support | 2026 |
| KKJ Property Limited | Real estate | 2016 |
| Knights Compass Limited | Professional & scientific | 2024 |
| Kold Air Ltd | Construction | 2025 |
| Koroni Limited | Health & social care | 2013 |
| KP GAS Developments Limited | Real estate | 2025 |
| Krasenlach Ltd | Professional & scientific | 2019 |
| KSR Plumbing and Heating Ltd | Construction | 2020 |
| KU Joinery & Building Limited | Construction | 2023 |
| Kudos Quality Ltd | Professional & scientific | 2017 |
| KW Continuing Health Care Solutions Ltd | Health & social care | 2018 |
| L&J Property Yorkshire Ltd | Real estate | 2024 |
| LA Scala COT Ltd | Hospitality | 2025 |
| LA Scala Cottingham Ltd | Administrative & support | 2016 |
| Lansbury Technologies Ltd | Construction | 2007 |
| Larn Investments Ltd | Real estate | 2023 |
| Laura Starky Ltd. | Other services | 2023 |
| Lausidan Limited | Health & social care | 2026 |
| Lawes Property Limited | Real estate | 2016 |
| Layla Alexandra Wellness Limited | Arts & recreation | 2025 |
| LCL Property Limited | Real estate | 2021 |
| Lead Consultancy Limited | Education | 2022 |
| Lead Talent Solutions Limited | Administrative & support | 2024 |
| LEE Duke Roofing Limited | Construction | 2021 |
| LEE Jones & SON Gardening Services Ltd | Administrative & support | 2021 |
| Lee-Bee Cornerstone Ltd | Wholesale & retail | 2025 |
| Leedan Shutters Ltd | Wholesale & retail | 2018 |
| Lehain & Lehain Holdings Limited | Financial services | 2014 |
| Level UP Perspective Ltd | Professional & scientific | 2024 |
| Lexo Limited | Real estate | 2023 |
| LH Hull Limited | Hospitality | 2025 |
| Liferyder Ltd | Wholesale & retail | 2014 |
| Lifestyle Corporation Limited | Wholesale & retail | 2019 |
| Linbetta Consulting Limited | Administrative & support | 2023 |
| Linetype Design Limited | Professional & scientific | 2013 |
| Lisa Dugdall Limited | Other services | 2003 |
| Little Harbour Town Ltd | Manufacturing | 2024 |