| Irvine Guesthouse Ltd | Hospitality | 2021 |
| Irvine Headstones Ltd | Other services | 2026 |
| Irvine Independent Funeral Directors Limited | Other services | 2022 |
| Irvine Local Ltd | Wholesale & retail | 2019 |
| Irvine Meadow Community Club CIC | Arts & recreation | 2016 |
| Irvine Meadow Football Club CIC | Arts & recreation | 2016 |
| Irvine Memorials Ltd | Manufacturing | 2022 |
| Irvine Mini Market (8) Ltd | Wholesale & retail | 2025 |
| Irvine Minimarket Ltd | Wholesale & retail | 2025 |
| Irvine Nails & Spa Ltd | Other services | 2023 |
| Irvine OFF Licence Ltd | Wholesale & retail | 2025 |
| Irvine Rangers Supporters Club Limited | Other services | 2021 |
| Irvine RAW K9 Supplies Ltd | Wholesale & retail | 2020 |
| Irvine Shawarma Ltd | Hospitality | 2025 |
| Irvine Sports Club | Arts & recreation | 2008 |
| Irvine Style CUT Ltd | Other services | 2021 |
| Irvine Taxi Call CS Ltd | Transport & logistics | 2026 |
| Irvine Taxi Call GS Ltd | Transport & logistics | 2025 |
| Irvine Taxi Call JD Ltd | Transport & logistics | 2026 |
| Irvine Taxi Call Ltd | Transport & logistics | 2023 |
| Irvine TOA | Transport & logistics | 2012 |
| Irvine Trade Hub Ltd | Wholesale & retail | 2024 |
| Irvine Tyre and Exhaust Limited | Administrative & support | 2008 |
| Irvine Valeting Centre Ltd | Administrative & support | 2019 |
| IT (Scotland) Limited | Transport & logistics | 2019 |
| Italio (Ayrshire) Ltd | Hospitality | 2019 |
| Itech (Scotland) Ltd. | Manufacturing | 2011 |
| Itech (Troon) Ltd. | Financial services | 2017 |
| Item Software (USA) Inc. | | 2001 |
| ITS (Scotland) Ltd | Transport & logistics | 2023 |
| Ixam Limited | Real estate | 2000 |
| J & a Quinn Limited | Wholesale & retail | 2007 |
| J & H Fencing Ltd | Construction | 2021 |
| J R Contracts (Scotland) Limited | Construction | 2019 |
| J S Groundworks & Civil Engineering Ltd | Construction | 2019 |
| J&H Tavern Ltd | Hospitality | 2026 |
| J. Moreland Ltd | Information & communication | 2015 |
| J.W Moreland Ltd | Information & communication | 2020 |
| Jack Civil Engineering Ltd | Administrative & support | 2023 |
| James Rodden Joinery Ltd | Construction | 2018 |
| James Walker & SON Limited | Construction | 2016 |
| Jamie Brown Films Ltd | Information & communication | 2020 |
| Jamiesons Motor Services Ltd | Wholesale & retail | 2013 |
| Janoon Ltd | Wholesale & retail | 2018 |
| JB Glazing Solutions Limited | Construction | 2021 |
| JBA Contracts Limited | Construction | 2019 |
| JBG Property Solutions Ltd | Real estate | 2024 |
| Jboffshorewind Ltd | Manufacturing | 2026 |
| JC Joiners Ltd | Construction | 2022 |
| JDB Water Construction Ltd | Construction | 2023 |
| Jeffrey Fabrication Ltd | Manufacturing | 2018 |
| Jesskam Fabrication Ltd | Professional & scientific | 2019 |
| JM Joiners (Irvine) Ltd | Construction | 2025 |
| JMB Cleaning Ltd | Administrative & support | 2013 |
| JMC Boxes & Packaging Ltd | Construction | 2014 |
| JMC Project Services Ltd | Professional & scientific | 2025 |
| JMK Meal Prep Ltd Ltd | Manufacturing | 2025 |
| Jmorris Contracts Ltd | Administrative & support | 2017 |
| John Aird (Holdings) Limited | Professional & scientific | 1995 |
| John D Dunlop Limited | Manufacturing | 2008 |
| Johnmac Ltd | Professional & scientific | 2023 |
| Johnny & Janet Taverns Ltd | Real estate | 2026 |
| Johnston Propertyworks Ltd | Real estate | 2024 |
| Johnston Roofworks Limited | Construction | 2024 |
| Jorcar Consultancy Limited | Professional & scientific | 2026 |
| Jord Geodesign Limited | Professional & scientific | 2019 |
| Joseph Scott Transport Limited | Transport & logistics | 2018 |
| Josh Nash Sound Ltd | Information & communication | 2022 |
| Joslive Ltd | Transport & logistics | 2025 |
| Joy M Limited | Professional & scientific | 2017 |
| Joyti Ltd | Hospitality | 2023 |
| JP Access & Services Ltd | Construction | 2025 |
| JRM Safety & Fire Ltd | Professional & scientific | 2024 |
| Jropeworx Limited | Construction | 2019 |
| JS Martin Properties Ltd | Construction | 2018 |
| JSP Convenience Store Ltd | Wholesale & retail | 2019 |
| Jujhar Singh Store Ltd | Wholesale & retail | 2020 |
| K a Tree Surgery Ltd | Agriculture & fishing | 2023 |
| K Brannan Ltd | Other services | 2019 |
| Ka-Mpire Holdco Ltd | Financial services | 2025 |
| Ka-Strategies Ltd | Wholesale & retail | 2025 |
| KA120 Limited | Other services | 2019 |
| KAD Access Ltd | Manufacturing | 2026 |
| KAL Rope Access Services Ltd | Professional & scientific | 2014 |
| Kaleidoscope Ayshire Ltd | Wholesale & retail | 2026 |
| Kaleidoscope Gifts Limited | Wholesale & retail | 2015 |
| Kang Foods Ltd | Hospitality | 2021 |
| Karizso Limited | Manufacturing | 2021 |
| Kcjs Engineering Ltd | Professional & scientific | 2018 |
| KD & Sons Scaffolding Services Ltd | Construction | 2014 |
| Kelvin Top-Set International Limited | Other services | 2009 |
| Kelvin Top-Set Limited | Other services | 2008 |
| Kelvin TS Trustees Limited | Administrative & support | 2022 |
| Kemnay Gardens Ltd | Other services | 2016 |
| Kennedy & Daughters Ltd | Hospitality | 2021 |
| Kennedysmith (Press) Limited | Manufacturing | 1998 |
| Kestrel Press (Irvine) Limited | Manufacturing | 1980 |
| Ketmar Limited | Hospitality | 2018 |
| Keystone Lets Limited | Real estate | 2023 |
| KGB Bodyshop Ltd | Wholesale & retail | 2019 |