diff --git a/src/routes/settings.import.tsx b/src/routes/settings.import.tsx
index edb52cd..6147976 100644
--- a/src/routes/settings.import.tsx
+++ b/src/routes/settings.import.tsx
@@ -1096,15 +1096,34 @@ function ImportPage() {
         }
       }
       if (withoutConflict.length > 0) {
-        const { data, error } = await supabase
-          .from(cfg.table as any)
-          .insert(withoutConflict as any)
-          .select("*");
-        if (error) {
-          errors.push(`Batch ${i / chunkSize + 1} (insert): ${error.message}`);
-        } else if (data) {
-          inserted += data.length;
-          inserted_rows.push(...data);
+        // For cases without external_id, upsert on case_number to avoid duplicate-key errors on re-import
+        if (cfg.table === "cases") {
+          const withCaseNum = withoutConflict.filter((r) => r.case_number);
+          const noCaseNum = withoutConflict.filter((r) => !r.case_number);
+          if (withCaseNum.length > 0) {
+            const { data, error } = await supabase
+              .from("cases" as any)
+              .upsert(withCaseNum as any, { onConflict: "case_number", ignoreDuplicates: false })
+              .select("*");
+            if (error) errors.push(`Batch ${i / chunkSize + 1} (upsert case_number): ${error.message}`);
+            else if (data) { inserted += data.length; inserted_rows.push(...(data as Row[])); }
+          }
+          if (noCaseNum.length > 0) {
+            const { data, error } = await supabase.from("cases" as any).insert(noCaseNum as any).select("*");
+            if (error) errors.push(`Batch ${i / chunkSize + 1} (insert): ${error.message}`);
+            else if (data) { inserted += data.length; inserted_rows.push(...(data as Row[])); }
+          }
+        } else {
+          const { data, error } = await supabase
+            .from(cfg.table as any)
+            .insert(withoutConflict as any)
+            .select("*");
+          if (error) {
+            errors.push(`Batch ${i / chunkSize + 1} (insert): ${error.message}`);
+          } else if (data) {
+            inserted += data.length;
+            inserted_rows.push(...data);
+          }
         }
       }
     }