diff --git a/addons/l10n_de/migrations/2.0/pre-migrate.py b/addons/l10n_de/migrations/2.0/pre-migrate.py
index 7737bf2b4ab..e2e59aca16c 100644
--- a/addons/l10n_de/migrations/2.0/pre-migrate.py
+++ b/addons/l10n_de/migrations/2.0/pre-migrate.py
@@ -21,6 +21,27 @@ def migrate(cr, version):
         """
     )
 
+    # As some people already upgraded, they will have renamed the C_1 tag to B_1. This doesn't come from the script but from the
+    # account_account_tags_data.xml. If they try to run this script now in the fix they get the error that B_1 already exists.
+    # To fix this we can check if it exists or not, and if it does then we don't run the script. This means that the ones
+    # that upgraded won't have the old tags data transferred to the new tags but they will still be able to have the updated sheet.
+    cr.execute(
+        """SELECT 1 FROM ir_model_data
+            WHERE module='l10n_de' AND name='tag_de_liabilities_bs_B_1'
+        """)
+    if cr.rowcount:
+        # If the script didn't run, we should remove the tags that have been replaced from ir_model_data too so they're
+        # not deleted by the ORM if they were already used.
+        cr.execute(
+            """DELETE FROM ir_model_data
+                WHERE module='l10n_de'
+                  AND name IN ('tag_de_liabilities_bs_F', 'tag_de_liabilities_bs_D_1', 'tag_de_liabilities_bs_D_2',
+                               'tag_de_liabilities_bs_D_3', 'tag_de_liabilities_bs_D_4', 'tag_de_liabilities_bs_D_5',
+                               'tag_de_liabilities_bs_D_6', 'tag_de_liabilities_bs_D_7', 'tag_de_liabilities_bs_D_8')
+            """
+        )
+        return
+
     rename_tag(cr, "tag_de_liabilities_bs_C_1", "tag_de_liabilities_bs_B_1")
     rename_tag(cr, "tag_de_liabilities_bs_C_2", "tag_de_liabilities_bs_B_2")
     rename_tag(cr, "tag_de_liabilities_bs_C_3", "tag_de_liabilities_bs_B_3")