diff --git a/src/components/cases/bulk-convert-to-collections-dialog.tsx b/src/components/cases/bulk-convert-to-collections-dialog.tsx
index 13f4b5b..796a08c 100644
--- a/src/components/cases/bulk-convert-to-collections-dialog.tsx
+++ b/src/components/cases/bulk-convert-to-collections-dialog.tsx
@@ -249,16 +249,47 @@ export function BulkConvertToCollectionsDialog({ open, onOpenChange, cases, onCr
       }
 
       const rows: any[] = [];
-      for (const r of selectedRows) {
-        const homeownerId = contactToHomeowner.get(r.contact_id);
-        if (!homeownerId) continue;
-        if (existingPairs.has(`${r.case_id}::${homeownerId}`)) continue;
-        rows.push({
-          case_id: r.case_id,
-          homeowner_id: homeownerId,
-          status: "none",
-          created_by: user?.id,
-        });
+      // Cases that already have ANY collection — skip in combine mode to avoid duplicates.
+      const casesWithExisting = new Set<string>();
+      for (const e of (existing ?? []) as any[]) casesWithExisting.add(e.case_id);
+
+      if (combine) {
+        // Group selected contacts by case, pick first as primary, attach others by name.
+        const byCase = new Map<string, typeof selectedRows>();
+        for (const r of selectedRows) {
+          if (!byCase.has(r.case_id)) byCase.set(r.case_id, [] as any);
+          byCase.get(r.case_id)!.push(r);
+        }
+        for (const [caseId, group] of byCase) {
+          if (casesWithExisting.has(caseId)) continue;
+          const primary = group[0];
+          const primaryHoId = contactToHomeowner.get(primary.contact_id);
+          if (!primaryHoId) continue;
+          const others = group.slice(1).map((r) => r.name);
+          const name =
+            others.length > 0
+              ? `${primary.name} + ${others.length} other${others.length === 1 ? "" : "s"}`
+              : null;
+          rows.push({
+            case_id: caseId,
+            homeowner_id: primaryHoId,
+            status: "none",
+            name,
+            created_by: user?.id,
+          });
+        }
+      } else {
+        for (const r of selectedRows) {
+          const homeownerId = contactToHomeowner.get(r.contact_id);
+          if (!homeownerId) continue;
+          if (existingPairs.has(`${r.case_id}::${homeownerId}`)) continue;
+          rows.push({
+            case_id: r.case_id,
+            homeowner_id: homeownerId,
+            status: "none",
+            created_by: user?.id,
+          });
+        }
       }
 
       if (includeEmpty) {