| Posti Jakelu Oy CVR 0109357-9 | OtherPerson with significant control | Siden 2022 | — | Aktiv |
| LähiTapiola Keskinäinen Vakuutusyhtiö CVR 0211034-2 | BoardBoard of Directors | Siden 2024 | — | Aktiv |
| Posti Group Oyj CVR 1531864-4 | OtherPerson with significant control | Siden 2021 | — | Aktiv |
| Retta Group Oy CVR 1969377-5 | BoardBoard of Directors | Siden 2018 | — | Opløst |
| Esperi Care Group Oy CVR 2333297-2 | BoardBoard of Directors | Siden 2022 | — | Aktiv |
| Posti Oy CVR 2344200-4 | OtherPerson with significant control | Siden 2023 | — | Aktiv |
| Posti Group Suomi Oy CVR 2365191-4 | OtherPerson with significant control | Siden 2023 | — | Aktiv |
| Realia Holding Oy CVR 2766772-9 | BoardBoard of Directors | Siden 2018 | — | Opløst |
| Posti Kuljetus Oy CVR 2786155-6 | BoardBoard of Directors | Siden 2026 | — | Aktiv |
| Posti Palvelut Oy CVR 2830428-4 | BoardBoard of Directors | Siden 2026 | — | Aktiv |
| Posti Messaging Oy CVR 2876876-7 | BoardBoard of Directors | Siden 2026 | — | Aktiv |
| Irepse Oy CVR 2989785-1 | BoardBoard of Directors | Siden 2022 | — | Aktiv |
