diff --git a/codelists/scripts/ad_hoc_old_style_snomed.json b/codelists/scripts/ad_hoc_old_style_snomed.json
new file mode 100644
index 000000000..bbf6adde2
--- /dev/null
+++ b/codelists/scripts/ad_hoc_old_style_snomed.json
@@ -0,0 +1,12 @@
+{
+    "comment": "Ad-hoc load of codelist as old-style",
+    "force_old_style": true,
+    "organisation": "user/pchavez",
+    "coding_systems": {
+        "snomedct": {
+            "id": "snomedct",
+            "release": "snomedct_4000_20250416"
+        }
+    },
+    "delimiter":"\t"
+}
diff --git a/codelists/scripts/bulk_import_codelists.py b/codelists/scripts/bulk_import_codelists.py
index dd3f2f336..f8782ce82 100755
--- a/codelists/scripts/bulk_import_codelists.py
+++ b/codelists/scripts/bulk_import_codelists.py
@@ -216,7 +216,10 @@ def update_name(name):
 
     # Remove extraneous whitespace from all columns of interest
     for column in relevant_df_columns:
-        codelist_df[column] = codelist_df[column].str.strip()
+        try:
+            codelist_df[column] = codelist_df[column].str.strip()
+        except AttributeError:
+            pass
 
     return codelist_df
 
@@ -237,7 +240,9 @@ def get_post_data(config, codelist_df, create_new_codelist, force_new_version):
         description = config["description_template"] % description
 
     post_data = {"coding_system_database_alias": release_db_alias, "tag": tag}
-    if coding_system_id in CODING_SYSTEMS_WITH_OLD_STYLE_CODELISTS:
+    if coding_system_id in CODING_SYSTEMS_WITH_OLD_STYLE_CODELISTS or config.get(
+        "force_old_style"
+    ):
         # create an old-style codelist/version with csv_data
         post_data["csv_data"] = codelist_df[["code", "term"]].to_csv()
     else: