diff --git a/pms/models/pms_checkin_partner.py b/pms/models/pms_checkin_partner.py
index ac21121d8..b0743f28e 100644
--- a/pms/models/pms_checkin_partner.py
+++ b/pms/models/pms_checkin_partner.py
@@ -855,6 +855,15 @@ class PmsCheckinPartner(models.Model):
             record.update(vals)
         return True
 
+    def action_undo_onboard(self):
+        for record in self.filtered(lambda c: c.state == "onboard"):
+            vals = {
+                "state": "precheckin",
+                "arrival": False,
+            }
+            record.update(vals)
+        return True
+
     def open_partner(self):
         """Utility method used to add an "View Customer" button in checkin partner views"""
         self.ensure_one()
diff --git a/pms/models/pms_reservation.py b/pms/models/pms_reservation.py
index 8a3275930..a5b453457 100644
--- a/pms/models/pms_reservation.py
+++ b/pms/models/pms_reservation.py
@@ -2441,6 +2441,15 @@ class PmsReservation(models.Model):
                 ).action_done()
         return True
 
+    def action_undo_onboard(self):
+        for record in self:
+            # Undo onboard all checkin partners:
+            record.checkin_partner_ids.filtered(
+                lambda check: check.state == "onboard"
+            ).action_undo_onboard()
+            record.state = "confirm"
+        return True
+
     def action_checkin_partner_view(self):
         self.ensure_one()
         tree_id = self.env.ref("pms.pms_checkin_partner_reservation_view_tree").id