diff --git a/csaxs_bec/bec_ipython_client/plugins/omny/omny_general_tools.py b/csaxs_bec/bec_ipython_client/plugins/omny/omny_general_tools.py
index 78e9892..74b03af 100644
--- a/csaxs_bec/bec_ipython_client/plugins/omny/omny_general_tools.py
+++ b/csaxs_bec/bec_ipython_client/plugins/omny/omny_general_tools.py
@@ -329,8 +329,12 @@ class TomoIDManager:
     """Registers a tomography measurement in the OMNY sample database
     and returns its assigned tomo ID.
 
-    Falls back to tomo ID 0 for non-production accounts (e.g. test
-    accounts like "gac-x01dc") which the server rejects.
+    Non-production accounts (e.g. test accounts like "gac-x01dc") register
+    against the test server (TEST_OMNY_URL) instead of production, so
+    testing still gets a real, incrementing tomo ID -- matching the
+    counter the samples-folder PDF upload reads from on that same test
+    host -- accepting that the eaccount recorded in that test database
+    won't be a real e-account.
 
     Usage:
         id_manager = TomoIDManager()
@@ -346,6 +350,7 @@ class TomoIDManager:
     """
 
     OMNY_URL = "https://v1p0zyg2w9n2k9c1.myfritz.net/samples/newmeasurement.php"
+    TEST_OMNY_URL = "https://omny-test.psi.ch/samples/newmeasurement.php"
     TMP_FILE = "~/currsamplesnr.txt"
     FALLBACK_TOMO_ID = 0
 
@@ -366,18 +371,23 @@ class TomoIDManager:
     ) -> int:
         """Register a new measurement and return the assigned tomo ID.
 
-        Returns FALLBACK_TOMO_ID (0) if the account is not a real e-account
-        or if the server cannot be reached / returns an unusable response.
+        Registers against OMNY_URL (production) for a real e-account, or
+        TEST_OMNY_URL (test server) otherwise. Returns FALLBACK_TOMO_ID (0)
+        only if the server actually can't be reached / returns an unusable
+        response.
         """
-        if not self._is_valid_eaccount(eaccount):
+        if self._is_valid_eaccount(eaccount):
+            omny_url = self.OMNY_URL
+        else:
+            omny_url = self.TEST_OMNY_URL
             logger.warning(
-                f"Account '{eaccount}' is not a valid e-account; "
-                f"skipping OMNY registration, using tomo ID {self.FALLBACK_TOMO_ID}."
+                f"Account '{eaccount}' is not a valid e-account; registering "
+                f"against the test server ({self.TEST_OMNY_URL}) instead of "
+                "production -- the eaccount recorded there won't be real."
             )
-            return self.FALLBACK_TOMO_ID
 
         url = (
-            f"{self.OMNY_URL}"
+            f"{omny_url}"
             f"?sample={sample_name}"
             f"&date={date}"
             f"&eaccount={eaccount}"
@@ -392,7 +402,7 @@ class TomoIDManager:
             result = subprocess.run(f"wget -q -O {tmp_file} '{url}'", shell=True, timeout=30)
             if result.returncode != 0:
                 raise OMNYToolsError(
-                    f"wget failed (exit code {result.returncode}) fetching tomo ID from {self.OMNY_URL}"
+                    f"wget failed (exit code {result.returncode}) fetching tomo ID from {omny_url}"
                 )
             with open(tmp_file) as f:
                 content = f.read().strip()