diff --git a/app/models.py b/app/models.py
index 5b37c2d0..280436fc 100644
--- a/app/models.py
+++ b/app/models.py
@@ -985,8 +985,13 @@ class Client(Base, ModelMixin):
     approved = sa.Column(sa.Boolean, nullable=False, default=False, server_default="0")
     description = sa.Column(sa.Text, nullable=True)
 
+    # a referral can be attached to a client
+    # so all users who sign up via the authorize screen are counted towards this referral
+    referral_id = sa.Column(sa.ForeignKey("referral.id"), nullable=True)
+
     icon = orm.relationship(File)
     user = orm.relationship(User)
+    referral = orm.relationship("Referral")
 
     def nb_user(self):
         return ClientUser.filter_by(client_id=self.id).count()
@@ -2251,7 +2256,7 @@ class Referral(Base, ModelMixin):
 
     code = sa.Column(sa.String(128), unique=True, nullable=False)
 
-    user = orm.relationship(User, foreign_keys=[user_id])
+    user = orm.relationship(User, foreign_keys=[user_id], backref="referrals")
 
     @property
     def nb_user(self) -> int:
diff --git a/migrations/versions/2021_102611_d67eab226ecd_.py b/migrations/versions/2021_102611_d67eab226ecd_.py
new file mode 100644
index 00000000..f9ec852c
--- /dev/null
+++ b/migrations/versions/2021_102611_d67eab226ecd_.py
@@ -0,0 +1,31 @@
+"""empty message
+
+Revision ID: d67eab226ecd
+Revises: a06066e3fbeb
+Create Date: 2021-10-26 11:35:13.448796
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'd67eab226ecd'
+down_revision = 'a06066e3fbeb'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('client', sa.Column('referral_id', sa.Integer(), nullable=True))
+    op.create_foreign_key(None, 'client', 'referral', ['referral_id'], ['id'])
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint(None, 'client', type_='foreignkey')
+    op.drop_column('client', 'referral_id')
+    # ### end Alembic commands ###