diff --git a/source/app/models/main.py b/source/app/models/main.py
index ae56046..521a598 100644
--- a/source/app/models/main.py
+++ b/source/app/models/main.py
@@ -3070,7 +3070,7 @@ class Facturas(BaseModel):
             .order_by(SQL('mf'))
             .scalar())
 
-        if inicio is None:
+        if inicio is None or inicio_serie > inicio:
             inicio = inicio_serie
         else:
             inicio += 1