diff --git a/downloader.py b/downloader.py
index 41e3c3f..3e13f91 100644
--- a/downloader.py
+++ b/downloader.py
@@ -121,9 +121,12 @@ def get_invoice_links(page: Page) -> list[dict]:
     seen = set()
 
     def _add_link(url: str, label: str, **meta) -> None:
-        if not url or url in seen:
+        if not url:
             return
-        seen.add(url)
+        dedupe_key = meta.get("reference_id") or url
+        if dedupe_key in seen:
+            return
+        seen.add(dedupe_key)
         entry = {"url": url, "label": label}
         entry.update(meta)
         links.append(entry)