| Ab Good Food Good Mood Oy | Hospitality | 2025 |
| Aminne Oy Ab | Professional & scientific | 1998 |
| Binder Finland Oy | Professional & scientific | 2018 |
| Björkö-Mossala Handel Ab | Real estate | 1977 |
| Fastighets Ab Houtskärs kursgård | Real estate | 2025 |
| Fastighetsaktiebolaget Skoltomten | Real estate | 1987 |
| Haandelsmans Ab | Hospitality | 2022 |
| Hagarell Invest Oy | Wholesale & retail | 2014 |
| Henriksson infraplanering Ab | Real estate | 2022 |
| Houtskär Boden Ab | Wholesale & retail | 1998 |
| Houtskärs El Ab | Construction | 2012 |
| Houtskärs Lantbruksservice Ab | Agriculture & fishing | 1987 |
| Houtskärs Mat och Bygg Ab | Wholesale & retail | 2000 |
| Houtskärs persontrafik öppet bolag | Transport & logistics | 2025 |
| JF-Consulting Oy | Professional & scientific | 1990 |
| JKE-Invest Ab Oy | Financial services | 2012 |
| Juslin Transport öppet bolag | Transport & logistics | 2020 |
| Långnäs Fritid Ab | Hospitality | 2015 |
| MTI-Marketing Oy | Professional & scientific | 1990 |
| Oy Hamnholm Ab | Hospitality | 2008 |
| Puppy Innovations Ky | Professional & scientific | 2016 |
| Quantum Electrodynamics Devices Oy | Professional & scientific | 2021 |
| REPS Oy Ab | Wholesale & retail | 2005 |
| SJUsolutions Ab | Administrative & support | 2025 |
| Saariston Puusepänliike Oy - Skärgårdens Snickeri Ab | Construction | 2006 |
| Scandinavian Lake Oy | Construction | 1999 |
| Storpensor multi-service OY AB | Construction | 2022 |
| Tikimo Fastighets Ab | Real estate | 1989 |