diff --git a/src/components/cases/convert-to-collections-dialog.tsx b/src/components/cases/convert-to-collections-dialog.tsx
index 2e0133d..30cefd7 100644
--- a/src/components/cases/convert-to-collections-dialog.tsx
+++ b/src/components/cases/convert-to-collections-dialog.tsx
@@ -429,6 +429,43 @@ export function ConvertToCollectionsDialog({
             )}
           </div>
 
+          <div className="border rounded-md p-3 space-y-2 bg-muted/20">
+            <label className="flex items-center gap-2 text-sm cursor-pointer">
+              <Checkbox
+                checked={combine}
+                onCheckedChange={(v) => setCombine(!!v)}
+              />
+              <span>
+                Combine into one collection (recommended)
+                <span className="block text-xs text-muted-foreground font-normal">
+                  Creates a single ledger for the case. Uncheck to make one ledger per homeowner.
+                </span>
+              </span>
+            </label>
+            {combine && selected.size > 1 && (
+              <div className="pt-1">
+                <Label className="text-xs">Primary homeowner</Label>
+                <Select
+                  value={primaryId ?? Array.from(selected)[0] ?? ""}
+                  onValueChange={(v) => setPrimaryId(v)}
+                >
+                  <SelectTrigger>
+                    <SelectValue placeholder="Pick primary homeowner" />
+                  </SelectTrigger>
+                  <SelectContent>
+                    {contacts
+                      .filter((c) => selected.has(c.id))
+                      .map((c) => (
+                        <SelectItem key={c.id} value={c.id}>
+                          {c.name}
+                        </SelectItem>
+                      ))}
+                  </SelectContent>
+                </Select>
+              </div>
+            )}
+          </div>
+
           <div className="border rounded-md p-3 space-y-2 bg-muted/20">
             <label className="flex items-center gap-2 text-sm cursor-pointer">
               <Checkbox
@@ -456,8 +493,9 @@ export function ConvertToCollectionsDialog({
             disabled={submitting || (selected.size === 0 && !includeEmpty)}
           >
             {submitting && <Loader2 className="h-4 w-4 mr-2 animate-spin" />}
-            Create {selected.size + (includeEmpty ? 1 : 0)} collection
-            {selected.size + (includeEmpty ? 1 : 0) === 1 ? "" : "s"}
+            {combine && selected.size > 0
+              ? `Create 1 combined collection${includeEmpty ? " + 1 empty" : ""}`
+              : `Create ${selected.size + (includeEmpty ? 1 : 0)} collection${selected.size + (includeEmpty ? 1 : 0) === 1 ? "" : "s"}`}
           </Button>
         </DialogFooter>
       </DialogContent>