diff --git a/fragdenstaat_de/fds_donation/remote_filing.py b/fragdenstaat_de/fds_donation/remote_filing.py
index b0b826e52..eebfae45e 100644
--- a/fragdenstaat_de/fds_donation/remote_filing.py
+++ b/fragdenstaat_de/fds_donation/remote_filing.py
@@ -1,3 +1,5 @@
+import os
+
 from django.conf import settings
 
 import requests
@@ -9,11 +11,28 @@ def backup_donation_file(file_handle, file_name):
     if not crdedentials or not webdav_url:
         return
     webdav_username, webdav_password = crdedentials.split(":")
+    count = 0
+    original_file_stem, orignal_file_ext = os.path.splitext(file_name)
+    while webdav_file_exists(file_name, webdav_url, webdav_username, webdav_password):
+        count += 1
+        file_name = f"{original_file_stem}-{count}.{orignal_file_ext}"
     upload_to_webdav(
         file_handle, file_name, webdav_url, webdav_username, webdav_password
     )
 
 
+def webdav_file_exists(
+    file_name: str, webdav_url: str, webdav_username: str, webdav_password: str
+) -> bool:
+    r = requests.get(
+        f"{webdav_url}/{file_name}",
+        auth=(webdav_username, webdav_password),
+    )
+    if r.status_code not in [200, 404]:
+        r.raise_for_status()
+    return r.status_code == 200
+
+
 def upload_to_webdav(
     file_handle, file_name, webdav_url, webdav_username, webdav_password
 ):