diff --git a/contrib/occtax/backend/occtax/migrations/e170d1902137_declare_permissions.py b/contrib/occtax/backend/occtax/migrations/e170d1902137_declare_permissions.py
new file mode 100644
index 0000000000..2521b0cc0e
--- /dev/null
+++ b/contrib/occtax/backend/occtax/migrations/e170d1902137_declare_permissions.py
@@ -0,0 +1,96 @@
+"""declare permissions
+
+Revision ID: e170d1902137
+Revises: 1b4f44762020
+Create Date: 2023-05-16 09:55:41.005029
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "e170d1902137"
+down_revision = "1b4f44762020"
+branch_labels = None
+depends_on = ("f051b88a57fd",)
+
+
+def upgrade():
+    op.execute(
+        """
+        INSERT INTO
+            gn_permissions.t_permissions_available (
+                id_module,
+                id_object,
+                id_action,
+                label,
+                scope_filter
+            )
+        SELECT
+            m.id_module,
+            o.id_object,
+            a.id_action,
+            v.label,
+            v.scope_filter
+        FROM
+            (
+                VALUES
+                     ('OCCTAX', 'ALL', 'C', True, 'Créer des relevés')
+                    ,('OCCTAX', 'ALL', 'R', True, 'Voir les relevés')
+                    ,('OCCTAX', 'ALL', 'U', True, 'Modifier les relevés')
+                    ,('OCCTAX', 'ALL', 'E', True, 'Exporter les relevés')
+                    ,('OCCTAX', 'ALL', 'D', True, 'Supprimer des relevés')
+            ) AS v (module_code, object_code, action_code, scope_filter, label)
+        JOIN
+            gn_commons.t_modules m ON m.module_code = v.module_code
+        JOIN
+            gn_permissions.t_objects o ON o.code_object = v.object_code
+        JOIN
+            gn_permissions.bib_actions a ON a.code_action = v.action_code
+        """
+    )
+    op.execute(
+        """
+        WITH bad_permissions AS (
+            SELECT
+                p.id_permission
+            FROM
+                gn_permissions.t_permissions p
+            JOIN gn_commons.t_modules m
+                    USING (id_module)
+            WHERE
+                m.module_code = 'OCCTAX'
+            EXCEPT
+            SELECT
+                p.id_permission
+            FROM
+                gn_permissions.t_permissions p
+            JOIN gn_permissions.t_permissions_available pa ON
+                (p.id_module = pa.id_module
+                    AND p.id_object = pa.id_object
+                    AND p.id_action = pa.id_action)
+        )
+        DELETE
+        FROM
+            gn_permissions.t_permissions p
+                USING bad_permissions bp
+        WHERE
+            bp.id_permission = p.id_permission;
+        """
+    )
+
+
+def downgrade():
+    op.execute(
+        """
+        DELETE FROM
+            gn_permissions.t_permissions_available pa
+        USING
+            gn_commons.t_modules m
+        WHERE
+            pa.id_module = m.id_module
+            AND
+            module_code = 'OCCTAX'
+        """
+    )