diff --git a/ereuse_devicehub/resources/device/models.py b/ereuse_devicehub/resources/device/models.py
index 5a40cfc6..f3971c15 100644
--- a/ereuse_devicehub/resources/device/models.py
+++ b/ereuse_devicehub/resources/device/models.py
@@ -75,11 +75,15 @@ def create_code(context):
     return hashcode.encode(_id)
 
 
-def create_phid(context):
-    _hid = Placeholder.query.order_by(Placeholder.id.desc()).first()
-    if _hid:
-        return str(_hid.id + 1)
-    return '1'
+def create_phid(context, count=1):
+    phid = str(Placeholder.query.filter(Placeholder.owner == g.user).count() + count)
+    if (
+        Placeholder.query.filter(Placeholder.owner == g.user)
+        .filter(Placeholder.phid == phid)
+        .count()
+    ):
+        return create_phid(context, count=count + 1)
+    return phid
 
 
 class Device(Thing):
@@ -901,8 +905,8 @@ class DisplayMixin:
 
 class Placeholder(Thing):
     id = Column(BigInteger, Sequence('placeholder_seq'), primary_key=True)
+    phid = Column(nullable=False, default=create_phid)
     pallet = Column(Unicode(), nullable=True)
-    phid = Column(Unicode(), nullable=False, default=create_phid)
     pallet.comment = "used for identification where from where is this placeholders"
     info = db.Column(CIText())
     components = Column(CIText())
@@ -912,6 +916,8 @@ class Placeholder(Thing):
     id_device_supplier.comment = (
         "Identification used for one supplier of one placeholders"
     )
+    id_device_internal = db.Column(CIText())
+    id_device_internal.comment = "Identification used internaly for the user"
 
     device_id = db.Column(
         BigInteger,