diff --git a/db/schema.ts b/db/schema.ts
old mode 100755
new mode 100644
index 0fe7a6d..006538b
--- a/db/schema.ts
+++ b/db/schema.ts
@@ -241,6 +241,7 @@ export const tenant_invites = pgTable("tenant_invites", {
   id: text("id").primaryKey(),
   landlord_id: text("landlord_id").references(() => users.id),
   property_id: text("property_id").references(() => properties.id),
+  lease_id: text("lease_id").references(() => leases.id),
   available_on: bigint("available_on", { mode: "number" }),
   invited_emails: text("invited_emails"), // JSON array of invited emails
   created_on: bigint("created_on", { mode: "number" }),
diff --git a/services/leaseService.ts b/services/leaseService.ts
index 839df86..2fc0601 100644
--- a/services/leaseService.ts
+++ b/services/leaseService.ts
@@ -233,6 +233,18 @@ export async function deleteLease(id: string) {
     .returning();
 }
 
+// Sign lease document
+export async function signLease(lease_id: string, user_id: string) {
+  const now = Date.now();
+  return await db.update(leases)
+    .set({
+      lease_document_url: `signed_${lease_id}_${now}`,
+      updated_on: now,
+    })
+    .where(eq(leases.id, lease_id))
+    .returning();
+}
+
 // Get lease statistics for an owner
 export async function getLeaseStatsByOwner(owner_id: string) {
   const allLeases = await getLeasesByOwner(owner_id);
@@ -268,10 +280,17 @@ export async function inviteLease(lease_id: string, inviteId?: string) {
   const lease = await getLeaseById(lease_id);
   if (!lease) return null;
 
+  const property_id = lease.property_id;
+  const landlord_id = lease.owner_id;
+
+  if (!property_id || !landlord_id) {
+    return null;
+  }
+
   const existing = await db.select().from(tenant_invites).where(
     and(
-      eq(tenant_invites.property_id, lease.property_id),
-      eq(tenant_invites.landlord_id, lease.owner_id),
+      eq(tenant_invites.property_id, property_id),
+      eq(tenant_invites.landlord_id, landlord_id),
     ),
   );
 
@@ -286,8 +305,8 @@ export async function inviteLease(lease_id: string, inviteId?: string) {
   // Create a new invite linking to this lease
   return await db.insert(tenant_invites).values({
     id: crypto.randomUUID(),
-    landlord_id: lease.owner_id,
-    property_id: lease.property_id,
+    landlord_id,
+    property_id,
     lease_id,
     available_on: null,
     invited_emails: JSON.stringify([]),