diff --git a/vault/lib/expiry-format.ts b/vault/lib/expiry-format.ts
new file mode 100644
index 0000000..ee5f290
--- /dev/null
+++ b/vault/lib/expiry-format.ts
@@ -0,0 +1,13 @@
+export function formatExpiry(expiresAt: string | null | undefined): string | null {
+  if (!expiresAt) return null;
+  const ms = new Date(expiresAt).getTime() - Date.now();
+  if (ms <= 0) return "Expired";
+  const totalMins = Math.floor(ms / 60000);
+  if (totalMins < 60) return `Expires in ${totalMins}m`;
+  const hrs = Math.floor(totalMins / 60);
+  const mins = totalMins % 60;
+  if (hrs < 24) return mins > 0 ? `Expires in ${hrs}h ${mins}m` : `Expires in ${hrs}h`;
+  const days = Math.floor(hrs / 24);
+  const remHrs = hrs % 24;
+  return remHrs > 0 ? `Expires in ${days}d ${remHrs}h` : `Expires in ${days}d`;
+}