| A-Toteuttajat Ky | Administrative & support | 2006 |
| A. Liikkanen Oy | Health & social care | 2017 |
| AA-Putki Oy | Construction | 2021 |
| AF Company Osakeyhtiö | Hospitality | 1997 |
| AHI Group Oy | Administrative & support | 2012 |
| AK-Maansiirto Oy | Construction | 2019 |
| ARI Finland OY | Construction | 2009 |
| Aaltsi Holding Oy | Construction | 2025 |
| Ab Flex Kraft Oy | Construction | 2001 |
| Ab Frauengarten Oy | Wholesale & retail | 1996 |
| Afinal Oy | Agriculture & fishing | 2011 |
| Annalan Kasvurengas Oy | Health & social care | 2002 |
| Arjamaria Oy | Education | 2013 |
| Atplast Oy | Manufacturing | 1998 |
| Autereen Taksiliikenne Oy | Transport & logistics | 2007 |
| Autohuolto Velj. Anttila Oy | Other services | 1989 |
| Avoin yhtiö T-market Nastolan Ruokakivi | Wholesale & retail | 1984 |
| Baku Invest Oy | Wholesale & retail | 1989 |
| Balladissa Oy | Hospitality | 1999 |
| BerCat Care Oy | Health & social care | 2012 |
| Blues Porch Oy | Information & communication | 2001 |
| Cardenal Oy | Administrative & support | 2018 |
| Citybirdy Oy | Construction | 2021 |
| Clinichem Oy Ltd | Manufacturing | 2000 |
| E. Niininen Oy | Construction | 2019 |
| ESTFIN Agro OÜ (SIVULIIKE) | Agriculture & fishing | 2008 |
| Eikka Invest Oy | Financial services | 2022 |
| Espoon Akvaariotukku Oy | Wholesale & retail | 2003 |
| Etelä-Iitin vesihuolto-osuuskunta | Water & waste | 2009 |
| Evibase Oy | Professional & scientific | 2019 |
| Factory Quality Services Oy | Manufacturing | 2025 |
| Fiksu Saneeraus Oy | Construction | 2023 |
| Finland Motorsport Circuit Holding Oy | Arts & recreation | 2023 |
| Finland Motorsport Circuit Oy | Arts & recreation | 2024 |
| Finlasko Oy | Hospitality | 2021 |
| Fropek Oy | Real estate | 1994 |
| Gran Rakennus Oy | Construction | 2017 |
| Grand Bay Oy | Information & communication | 2024 |
| HK-Markkinointi Oy | Wholesale & retail | 1991 |
| HM Huoltopalvelu Oy | Other services | 2025 |
| Huraa OY | Construction | 2023 |
| Halton Foodservice Oy | Manufacturing | 2008 |
| Halton Health and Cleanroom Oy | Professional & scientific | 2001 |
| Halton Marine Oy | Manufacturing | 2008 |
| Halton Oy | Manufacturing | 2003 |
| Halton Ventures Oy | Professional & scientific | 1983 |
| Hammaslääkärin vastaanotto Leena Simola Oy | Health & social care | 2017 |
| Happy Konie Oy | Arts & recreation | 2015 |
| Harjukorpi Oy | Transport & logistics | 2019 |
| Harwidson Oy | Financial services | 2017 |
| Haukkavuoren Laskenta Oy | Professional & scientific | 2019 |
| Hermes bahwer Oy | Hospitality | 2024 |
| HockeyMoms Oy | Manufacturing | 2019 |
| Hoivakoti Aamurusko Oy | Health & social care | 2015 |
| Hormitähti Oy | Administrative & support | 2008 |
| Hotel Lima Oy | Health & social care | 2019 |
| Huomiotilit Oy | Professional & scientific | 2023 |
| Icoma Oy | Manufacturing | 2021 |
| IdeaServices Oy | Construction | 2007 |
| Iitin Energiaosuuskunta | Energy | 2001 |
| Iitin Imarre Oy | Wholesale & retail | 2019 |
| Iitin Kiinteistöpalvelu Oy | Administrative & support | 2011 |
| Iitin Konetalo Ky | Manufacturing | 2012 |
| Iitin Kymppikoneistus Oy | Manufacturing | 1992 |
| Iitin Lehti Osakeyhtiö | Information & communication | 1955 |
| Iitin Maatilatori Oy | Wholesale & retail | 2017 |
| Iitin Murske Oy | Mining & quarrying | 2005 |
| Iitin Rakennuspalvelu Oy | Construction | 2011 |
| Iitin Saneerausapu Oy | Construction | 2017 |
| Iitin Säästöranta Oy | Real estate | 1993 |
| Iitin Tili Oy | Professional & scientific | 1996 |
| Iitin Vuokratalot Oy | Real estate | 1982 |
| Iitin kaivuu- ja metsäpalvelut Oy | Agriculture & fishing | 2025 |
| Iitin kone ja asennus Oy | Construction | 2020 |
| Iitin kuljetus & palvelu Oy | Transport & logistics | 2015 |
| Iitti Golf Oy | Arts & recreation | 2002 |
| Iitti Timber Oy | Manufacturing | 2022 |
| Insinööritoimisto Kari Rinne Oy | Professional & scientific | 2001 |
| Investica Oy | Administrative & support | 2006 |
| J-Voima Oy | Professional & scientific | 2013 |
| JALEX Transport OY | Transport & logistics | 2025 |
| Jhl-Rakenne OY | Construction | 2002 |
| JV Monihomma Oy | Construction | 2014 |
| JaHy Muutto- ja Kuljetuspalvelut Oy | Transport & logistics | 2025 |
| Jamiro Oy | Hospitality | 2012 |
| Jari Leino Oy | Transport & logistics | 2009 |
| Järvenpään Pinnoitus Oy | Construction | 1992 |
| KAKURA Oy | Construction | 2019 |
| KMJ Kiinteistöt Oy | Real estate | 2023 |
| KSH-PALVELUT LIMITED,Suomen sivuliike | Other services | 2017 |
| KVN Maansiirto Oy | Construction | 2026 |
| KYMIOSA Oy | Wholesale & retail | 2024 |
| Kala-Iitti Oy | Manufacturing | 2019 |
| Kaupe Oy | Manufacturing | 1977 |
| Kausalan Autokatsastus Oy | Professional & scientific | 2018 |
| Kausalan Autokorikeskus Oy | Real estate | 2002 |
| Kausalan Autotarvike Oy | Wholesale & retail | 1981 |
| Kausalan Kauppapuutarha Kommandiittiyhtiö | Other services | 1979 |
| Kausalan Kiinteistö- ja Siivouspalvelu Oy | Administrative & support | 1992 |
| Kausalan Koneistus Ky | Manufacturing | 1989 |